From 0baa5a6db17fe0ff179fc20ed2d3960691e8c9f6 Mon Sep 17 00:00:00 2001
From: Sergei Pavlov <spavlov@servicetitan.com>
Date: Thu, 4 Jan 2024 20:31:21 -0800
Subject: [PATCH] Use implicit `<Using ` featurn in Direcory.Build.props to
 remove thousands lines of boilerplate code

---
 Directory.Build.props                                  | 10 +++++++++-
 Extensions/TestCommon/AssemblyExtensions.cs            |  2 --
 Extensions/TestCommon/Model/Bar.cs                     |  1 -
 Extensions/TestCommon/Model/Bar2.cs                    |  1 -
 Extensions/TestCommon/Model/LinqCompilerContainer.cs   |  1 -
 Extensions/TestCommon/Tests/TestConfigurationTest.cs   |  1 -
 .../Xtensive.Orm.BulkOperations.Tests/ContainsTest.cs  |  2 --
 .../Xtensive.Orm.BulkOperations.Tests/Extensions.cs    |  1 -
 ...ra0560_ChangeFieldWhichDefinedInAncestorClassBug.cs |  3 ---
 .../IssueJira0565_IgnoringTakeMethodOnTranslation.cs   |  2 --
 .../Issues/JoinedTableAsSourceForDelete.cs             |  1 -
 Extensions/Xtensive.Orm.BulkOperations.Tests/Other.cs  |  4 ----
 .../ReferenceFields.cs                                 |  2 --
 .../Xtensive.Orm.BulkOperations.Tests/Structures.cs    |  1 -
 .../Xtensive.Orm.BulkOperations/BulkExtensions.cs      |  4 ----
 .../Internals/AddValueContext.cs                       |  1 -
 .../Internals/BaseSqlVisitor.cs                        |  2 --
 .../Internals/BulkDeleteOperation.cs                   |  4 ----
 .../Internals/BulkUpdateOperation.cs                   |  5 -----
 .../Internals/ExpressionExtensions.cs                  |  2 --
 .../Internals/ExpressionVisitor.cs                     |  2 --
 .../Internals/InsertOperation.cs                       |  5 -----
 .../Xtensive.Orm.BulkOperations/Internals/Operation.cs |  5 -----
 .../Internals/QueryOperation.cs                        |  3 ---
 .../Internals/SetOperation.cs                          |  3 ---
 .../Internals/SetStatement.cs                          |  2 --
 .../Xtensive.Orm.BulkOperations/Internals/Updatable.cs |  3 ---
 .../Internals/WellKnownMembers.cs                      |  2 --
 .../AccessToLocalizationOnUpgrade.cs                   |  1 -
 .../CurrentThreadTest.cs                               |  2 --
 .../Xtensive.Orm.Localization.Tests/DirectEditTest.cs  |  1 -
 .../LocalizationScopeTest.cs                           |  1 -
 .../Xtensive.Orm.Localization.Tests/Model/Page.cs      |  1 -
 .../Model/PageLocalization.cs                          |  1 -
 .../MultipleNodesTest.cs                               |  1 -
 .../ProjectionToCustomTypesTests.cs                    |  2 --
 .../Xtensive.Orm.Localization.Tests/QueryTests.cs      |  3 ---
 .../Configuration/Elements/ConfigurationSection.cs     |  1 -
 .../Configuration/LocalizationConfiguration.cs         |  2 --
 .../Internals/LocalizationExpressionBuilder.cs         |  2 --
 .../Internals/TypeLocalizationInfo.cs                  |  1 -
 .../Internals/TypeLocalizationMap.cs                   |  2 --
 Extensions/Xtensive.Orm.Localization/Localization.cs   |  1 -
 .../Xtensive.Orm.Localization/LocalizationContext.cs   |  2 --
 .../Xtensive.Orm.Localization/LocalizationPolicy.cs    |  1 -
 .../Xtensive.Orm.Localization/LocalizationSet.cs       |  1 -
 .../Xtensive.Orm.Localization/QueryExtensions.cs       |  1 -
 .../Xtensive.Orm.Reprocessing.Tests/Tests/Context.cs   |  4 ----
 .../Tests/DeadlockReprocessing.cs                      |  4 ----
 .../Xtensive.Orm.Reprocessing.Tests/Tests/Other.cs     |  1 -
 .../Tests/UniqueConstraintViolationReprocessing.cs     |  2 --
 .../Configuration/ConfigurationSection.cs              |  1 -
 .../Configuration/ReprocessingConfiguration.cs         |  1 -
 .../DomainBuildErrorEventArgs.cs                       |  1 -
 Extensions/Xtensive.Orm.Reprocessing/DomainBuilder.cs  |  2 --
 .../Xtensive.Orm.Reprocessing/DomainExtensions.cs      |  1 -
 .../Xtensive.Orm.Reprocessing/ExecuteActionStrategy.cs |  1 -
 .../Xtensive.Orm.Reprocessing/ExecuteErrorEventArgs.cs |  1 -
 .../Xtensive.Orm.Reprocessing/ExecutionContext.cs      |  1 -
 .../IExecuteActionStrategy.cs                          |  1 -
 .../Xtensive.Orm.Reprocessing/IExecuteConfiguration.cs |  1 -
 .../Internals/ExecuteConfiguration.cs                  |  1 -
 .../Xtensive.Orm.Reprocessing/ReprocessAttribute.cs    |  1 -
 .../ReprocessableDomainBuilder.cs                      |  1 -
 .../RollbackTransactionException.cs                    |  1 -
 Extensions/Xtensive.Orm.Security.Tests/Model/Branch.cs |  1 -
 .../Xtensive.Orm.Security.Tests/Model/Employee.cs      |  1 -
 .../Xtensive.Orm.Security.Tests/Model/VipCustomer.cs   |  1 -
 .../Permissions/CustomerPermission.cs                  |  2 --
 .../Permissions/VipCustomerPermission.cs               |  2 --
 .../Roles/AircraftManagerRole.cs                       |  2 --
 .../Roles/AutomobileManagerRole.cs                     |  2 --
 .../Roles/BranchOfficeManagerRole.cs                   |  2 --
 .../Roles/SalesManagerRole.cs                          |  2 --
 .../Roles/SalesPersonRole.cs                           |  2 --
 .../Xtensive.Orm.Security.Tests/SecurityTestBase.cs    |  1 -
 .../Tests/HashingServicesTests.cs                      |  3 ---
 .../Tests/ImpersonationContextTests.cs                 |  1 -
 .../Tests/PermissionSetTests.cs                        |  1 -
 .../AuthenticationServiceConfigurationElement.cs       |  1 -
 .../Configuration/Elements/ConfigurationSection.cs     |  1 -
 .../Elements/HashingServiceConfigurationElement.cs     |  1 -
 .../Configuration/SecurityConfiguration.cs             |  1 -
 .../Cryptography/GenericHashingService.cs              |  2 --
 .../Cryptography/PlainHashingService.cs                |  1 -
 Extensions/Xtensive.Orm.Security/GenericPrincipal.cs   |  1 -
 .../Xtensive.Orm.Security/ImpersonationContext.cs      |  1 -
 Extensions/Xtensive.Orm.Security/Interfaces/IRole.cs   |  1 -
 Extensions/Xtensive.Orm.Security/Permission.cs         |  2 --
 Extensions/Xtensive.Orm.Security/PermissionSet.cs      |  2 --
 Extensions/Xtensive.Orm.Security/Principal.cs          |  1 -
 Extensions/Xtensive.Orm.Security/Role.cs               |  1 -
 .../Xtensive.Orm.Security/SecureQueryRootBuilder.cs    |  3 ---
 .../Services/GenericAuthenticationService.cs           |  2 --
 .../Xtensive.Orm.Tracking.Tests/Model/MyEntity.cs      |  1 -
 .../Model/MyEntitySetItem.cs                           |  3 ---
 Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEnum.cs |  3 ---
 .../Model/MyReferenceProperty.cs                       |  3 ---
 .../Xtensive.Orm.Tracking.Tests/Model/MyStructure.cs   |  3 ---
 Extensions/Xtensive.Orm.Tracking.Tests/TestHelper.cs   |  1 -
 .../TrackingMonitorTests.cs                            |  2 --
 .../TrackingStackFrameTests.cs                         |  1 -
 .../Xtensive.Orm.Tracking.Tests/TrackingTestBase.cs    |  1 -
 .../Interfaces/IDomainTrackingMonitor.cs               |  1 -
 .../Xtensive.Orm.Tracking/Interfaces/ITrackingItem.cs  |  1 -
 .../Interfaces/ITrackingMonitor.cs                     |  1 -
 .../Internals/DomainTrackingMonitor.cs                 |  1 -
 .../Internals/SessionTrackingMonitor.cs                |  3 ---
 .../Xtensive.Orm.Tracking/Internals/TrackingItem.cs    |  3 ---
 .../Xtensive.Orm.Tracking/Internals/TrackingMonitor.cs |  1 -
 .../Internals/TrackingStackFrame.cs                    |  1 -
 .../TrackingCompletedEventArgs.cs                      |  2 --
 Extensions/Xtensive.Orm.Tracking/TrackingItemState.cs  |  1 -
 Extensions/Xtensive.Orm.Web.Tests/ActionFilterTest.cs  |  3 ---
 Extensions/Xtensive.Orm.Web.Tests/MiddlewareTest.cs    |  3 ---
 Extensions/Xtensive.Orm.Web.Tests/WebTestBase.cs       |  1 -
 .../Xtensive.Orm.Web/Filters/SessionActionFilter.cs    |  2 --
 .../Middleware/OpenSessionMiddleware.cs                |  2 --
 Extensions/Xtensive.Orm.Web/SessionAccessor.cs         |  1 -
 .../Xtensive.Orm.Web/StartupConfigurationExtensions.cs |  1 -
 Extensions/Xtensive.Orm.Web/WellKnownTypes.cs          |  1 -
 .../Sql.Drivers.Firebird/Connection.cs                 |  1 -
 .../Sql.Drivers.Firebird/Constants.cs                  |  1 -
 .../Sql.Drivers.Firebird/Driver.cs                     |  1 -
 .../Sql.Drivers.Firebird/DriverFactory.cs              |  3 ---
 .../Sql.Drivers.Firebird/Resources/Strings.Designer.cs |  1 -
 .../Sql.Drivers.Firebird/v2_5/Compiler.cs              |  3 ---
 .../Sql.Drivers.Firebird/v2_5/Driver.cs                |  1 -
 .../Sql.Drivers.Firebird/v2_5/Extractor.Queries.cs     |  1 -
 .../Sql.Drivers.Firebird/v2_5/Extractor.cs             |  4 ----
 .../Sql.Drivers.Firebird/v2_5/ServerInfoProvider.cs    |  1 -
 .../Sql.Drivers.Firebird/v2_5/Translator.cs            |  2 --
 .../Sql.Drivers.Firebird/v2_5/TypeMapper.cs            |  1 -
 .../Sql.Drivers.Firebird/v4_0/Compiler.cs              |  2 --
 .../Sql.Drivers.Firebird/v4_0/Driver.cs                |  1 -
 .../Sql.Drivers.Firebird/v4_0/Extractor.cs             |  4 ----
 .../Sql.Drivers.Firebird/v4_0/TypeMapper.cs            |  1 -
 .../Advanced/CustomLinqCompilerTest.cs                 |  2 --
 .../Advanced/CustomSqlCompilerTest.cs                  |  2 --
 .../Advanced/JoinsAndSubqueriesTest.cs                 |  2 --
 Orm/Xtensive.Orm.Manual/Attributes/AttributesTest.cs   |  1 -
 .../Caching/CalculatedValueCachingTest.cs              |  3 ---
 Orm/Xtensive.Orm.Manual/Concurrency/LockingTest.cs     |  3 ---
 Orm/Xtensive.Orm.Manual/Concurrency/VersionsTest.cs    |  3 ---
 .../DomainAndSession/DomainAndSessionSample.cs         |  1 -
 Orm/Xtensive.Orm.Manual/Entities/TestFixture.cs        |  1 -
 Orm/Xtensive.Orm.Manual/EntitySets/EntitySetsTest.cs   |  3 ---
 .../FutureQueries/FutureQueriesTest.cs                 |  2 --
 Orm/Xtensive.Orm.Manual/Indexes/TestFixture.cs         |  2 --
 Orm/Xtensive.Orm.Manual/Intro/CheatSheetTest.cs        |  2 --
 Orm/Xtensive.Orm.Manual/Intro/HelloWorldTest.cs        |  1 -
 .../CustomKeyGenerators/CustomKeyGeneratorsTest.cs     |  1 -
 .../ModellingDomain/AuditAndOpenGenericsTest.cs        |  3 ---
 .../ModellingDomain/IndexAttributeTest.cs              |  3 ---
 Orm/Xtensive.Orm.Manual/Persistent/TestFixture.cs      |  1 -
 Orm/Xtensive.Orm.Manual/Prefetch/PrefetchTest.cs       |  3 ---
 .../Services/DirectSqlAccessorTest.cs                  |  2 --
 .../Services/DirectStateAccessorTest.cs                |  2 --
 Orm/Xtensive.Orm.Manual/Structures/TestFixture.cs      |  2 --
 .../Transactions/NestedTransactionsTest.cs             |  1 -
 .../Transactions/SessionSwitchingTest.cs               |  2 --
 Orm/Xtensive.Orm.Manual/Upgrade/Model_1/Model.cs       |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Model.cs       |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Upgrader.cs    |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Model.cs       |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Upgrader.cs    |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Model.cs       |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Upgrader.cs    |  2 --
 .../Upgrade/UpgradeHandlerEnabler.cs                   |  1 -
 Orm/Xtensive.Orm.Manual/Upgrade/UpgradeTest.cs         |  2 --
 Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Connection.cs |  2 --
 Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Driver.cs     |  1 -
 .../Sql.Drivers.MySql/DriverFactory.cs                 |  4 ----
 .../Sql.Drivers.MySql/Resources/Strings.Designer.cs    |  1 -
 .../Sql.Drivers.MySql/v5_0/Compiler.cs                 |  2 --
 .../Sql.Drivers.MySql/v5_0/Extractor.cs                |  4 ----
 .../Sql.Drivers.MySql/v5_0/ServiceInfoProvider.cs      |  1 -
 .../Sql.Drivers.MySql/v5_0/Translator.cs               |  3 ---
 .../Sql.Drivers.MySql/v5_0/TypeMapper.cs               |  2 --
 .../Sql.Drivers.MySql/v5_6/Compiler.cs                 |  2 --
 .../Sql.Drivers.MySql/v5_6/Translator.cs               |  1 -
 .../Sql.Drivers.MySql/v5_7/Translator.cs               |  1 -
 .../Sql.Drivers.MySql/v8_0/Translator.cs               |  1 -
 .../Orm.Providers.Oracle/SqlCompiler.cs                |  2 --
 Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Driver.cs   |  1 -
 .../Sql.Drivers.Oracle/DriverFactory.cs                |  4 ----
 .../Sql.Drivers.Oracle/Resources/Strings.Designer.cs   |  1 -
 .../Sql.Drivers.Oracle/v09/Compiler.cs                 |  2 --
 .../Sql.Drivers.Oracle/v09/Driver.cs                   |  1 -
 .../Sql.Drivers.Oracle/v09/Extractor.cs                |  5 -----
 .../Sql.Drivers.Oracle/v09/ServerInfoProvider.cs       |  1 -
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 .../Sql.Drivers.Oracle/v09/TypeMapper.cs               |  1 -
 .../Sql.Drivers.Oracle/v10/Compiler.cs                 |  1 -
 .../Sql.Drivers.Oracle/v10/Extractor.cs                |  1 -
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 .../Sql.Drivers.Oracle/v11/Compiler.cs                 |  1 -
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 .../Sql.Drivers.Oracle/v11/TypeMapper.cs               |  1 -
 .../Orm.Providers.PostgreSql/DomainHandler.cs          |  3 ---
 .../Orm.Providers.PostgreSql/SqlCompiler.cs            |  2 --
 .../Sql.Drivers.PostgreSql/Connection.cs               |  2 --
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 .../Sql.Drivers.PostgreSql/PostgreSqlTypeMapper.cs     |  1 -
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 .../Sql.Drivers.PostgreSql/v10_0/Translator.cs         |  1 -
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 .../Sql.Drivers.PostgreSql/v8_0/Driver.cs              |  1 -
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 .../Sql.Drivers.PostgreSql/v8_0/PathMapper.cs          |  1 -
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 .../Sql.Drivers.PostgreSql/v8_1/Driver.cs              |  1 -
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 .../Sql.Drivers.PostgreSql/v8_2/Translator.cs          |  1 +
 .../Sql.Drivers.PostgreSql/v8_2/TypeMapper.cs          |  1 -
 .../Sql.Drivers.PostgreSql/v8_3/Compiler.cs            |  3 ---
 .../Sql.Drivers.PostgreSql/v8_3/Driver.cs              |  1 -
 .../Sql.Drivers.PostgreSql/v8_3/Translator.cs          |  2 --
 .../Sql.Drivers.PostgreSql/v8_3/TypeMapper.cs          |  1 -
 .../Sql.Drivers.PostgreSql/v8_4/Extractor.cs           |  1 -
 Orm/Xtensive.Orm.PostgreSql/WellKnownTypes.cs          |  2 --
 .../Orm.Providers.SqlServer/DomainHandler.cs           |  2 --
 .../SearchConditionCompilerV09.cs                      |  2 --
 .../Orm.Providers.SqlServer/SqlCompiler.cs             |  3 ---
 .../Sql.Drivers.SqlServer/Connection.cs                |  3 ---
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 .../Sql.Drivers.SqlServer/DriverFactory.cs             |  4 ----
 .../Sql.Drivers.SqlServer/ErrorMessageParser.cs        |  3 ---
 .../Sql.Drivers.SqlServer/InternalHelpers.cs           |  1 -
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 Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Driver.cs   |  1 -
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 Orm/Xtensive.Orm.Tests.Core/Logging/LogManagerTests.cs |  2 --
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 .../Application/ConsoleMessageWriter.cs                |  1 -
 Weaver/Xtensive.Orm.Weaver/Application/Program.cs      |  1 -
 Weaver/Xtensive.Orm.Weaver/AssemblyChecker.cs          |  1 -
 Weaver/Xtensive.Orm.Weaver/AssemblyProcessor.cs        |  3 ---
 Weaver/Xtensive.Orm.Weaver/AssemblyResolver.cs         |  2 --
 Weaver/Xtensive.Orm.Weaver/Extensions.cs               |  2 --
 Weaver/Xtensive.Orm.Weaver/FileHelper.cs               |  1 -
 Weaver/Xtensive.Orm.Weaver/MessageLogger.cs            |  2 --
 Weaver/Xtensive.Orm.Weaver/ProcessorConfiguration.cs   |  2 --
 Weaver/Xtensive.Orm.Weaver/ProcessorContext.cs         |  2 --
 Weaver/Xtensive.Orm.Weaver/ProcessorMessage.cs         |  1 -
 Weaver/Xtensive.Orm.Weaver/ProcessorStageAttribute.cs  |  1 -
 Weaver/Xtensive.Orm.Weaver/PropertyInfo.cs             |  2 --
 Weaver/Xtensive.Orm.Weaver/ReferenceRegistry.cs        |  1 -
 Weaver/Xtensive.Orm.Weaver/StageFailedException.cs     |  1 -
 .../Stages/FindPersistentTypesStage.cs                 |  3 ---
 .../Stages/ImportReferencesStage.cs                    |  3 ---
 .../Stages/ModifyPersistentTypesStage.cs               |  1 -
 Weaver/Xtensive.Orm.Weaver/Tasks/AddAttributeTask.cs   |  1 -
 .../Xtensive.Orm.Weaver/Tasks/ImplementFactoryTask.cs  |  2 --
 .../Tasks/ImplementFieldAccessorTask.cs                |  2 --
 .../Tasks/ImplementInitializablePatternTask.cs         |  2 --
 .../Tasks/ImplementKeySetterTask.cs                    |  1 -
 .../Tasks/RemoveBackingFieldTask.cs                    |  1 -
 Weaver/Xtensive.Orm.Weaver/TypeIdentity.cs             |  1 -
 Weaver/Xtensive.Orm.Weaver/TypeInfo.cs                 |  2 --
 Weaver/Xtensive.Orm.Weaver/WeavingHelper.cs            |  2 --
 Weaver/Xtensive.Orm.Weaver/WellKnown.cs                |  1 -
 2835 files changed, 23 insertions(+), 4976 deletions(-)

diff --git a/Directory.Build.props b/Directory.Build.props
index 6ad5e13a10..26d84ac533 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -49,7 +49,7 @@
     <!-- hard binding to net8, no property and env variable allowed-->
     <TargetFrameworks>net8.0</TargetFrameworks>
   </PropertyGroup>
-  
+
   <!-- Debug-NET7, Release-NET7 are mostly for development convenience -->
   <PropertyGroup Condition = "$(Configuration.Contains('NET7')) == 'true'">
     <!-- hard binding to net7, no property and env variable allowed-->
@@ -127,6 +127,14 @@
     <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Using Include="System" />
+    <Using Include="System.Collections.Generic" />
+    <Using Include="System.Linq" />
+    <Using Include="System.Threading" />
+    <Using Include="System.Threading.Tasks" />
+  </ItemGroup>
+
   <ItemGroup>
     <SourceRoot Include="$(SolutionDir)"/>
     <PackageReference Condition="$(DoGeneratePackage) == 'true'"
diff --git a/Extensions/TestCommon/AssemblyExtensions.cs b/Extensions/TestCommon/AssemblyExtensions.cs
index ad71969fd0..87d1f20f47 100644
--- a/Extensions/TestCommon/AssemblyExtensions.cs
+++ b/Extensions/TestCommon/AssemblyExtensions.cs
@@ -1,6 +1,4 @@
-using System;
 using System.Reflection;
-using System.Collections.Generic;
 using System.Text;
 using System.Configuration;
 
diff --git a/Extensions/TestCommon/Model/Bar.cs b/Extensions/TestCommon/Model/Bar.cs
index b6e04e1f44..41514c9633 100644
--- a/Extensions/TestCommon/Model/Bar.cs
+++ b/Extensions/TestCommon/Model/Bar.cs
@@ -1,4 +1,3 @@
-using System;
 using Xtensive.Orm;
 
 namespace TestCommon.Model
diff --git a/Extensions/TestCommon/Model/Bar2.cs b/Extensions/TestCommon/Model/Bar2.cs
index 48c3152148..1f07dedd15 100644
--- a/Extensions/TestCommon/Model/Bar2.cs
+++ b/Extensions/TestCommon/Model/Bar2.cs
@@ -1,4 +1,3 @@
-using System;
 using Xtensive.Orm;
 
 namespace TestCommon.Model
diff --git a/Extensions/TestCommon/Model/LinqCompilerContainer.cs b/Extensions/TestCommon/Model/LinqCompilerContainer.cs
index 5f52b18ee4..d4ddd85fd9 100644
--- a/Extensions/TestCommon/Model/LinqCompilerContainer.cs
+++ b/Extensions/TestCommon/Model/LinqCompilerContainer.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Extensions/TestCommon/Tests/TestConfigurationTest.cs b/Extensions/TestCommon/Tests/TestConfigurationTest.cs
index d6eb9f01f5..f0d1e1ff8d 100644
--- a/Extensions/TestCommon/Tests/TestConfigurationTest.cs
+++ b/Extensions/TestCommon/Tests/TestConfigurationTest.cs
@@ -1,4 +1,3 @@
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/ContainsTest.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/ContainsTest.cs
index 846f628e59..0144a5b6f9 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/ContainsTest.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/ContainsTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.BulkOperations.ContainsTestModel;
 using Xtensive.Orm.Configuration;
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/Extensions.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/Extensions.cs
index 12e0346781..ac628a584f 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/Extensions.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/Extensions.cs
@@ -1,4 +1,3 @@
-using System;
 using NUnit.Framework;
 using NUnit.Framework.Constraints;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0560_ChangeFieldWhichDefinedInAncestorClassBug.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0560_ChangeFieldWhichDefinedInAncestorClassBug.cs
index 62deb808ab..ccf5ed8ba5 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0560_ChangeFieldWhichDefinedInAncestorClassBug.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0560_ChangeFieldWhichDefinedInAncestorClassBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.10.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Model;
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0565_IgnoringTakeMethodOnTranslation.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0565_IgnoringTakeMethodOnTranslation.cs
index eb4e745c36..552dc6165c 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0565_IgnoringTakeMethodOnTranslation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/IssueJira0565_IgnoringTakeMethodOnTranslation.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.02.06
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using TestCommon.Model;
 using Xtensive.Orm.Providers;
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/JoinedTableAsSourceForDelete.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/JoinedTableAsSourceForDelete.cs
index 20218136e8..684ed8137b 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/JoinedTableAsSourceForDelete.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/Issues/JoinedTableAsSourceForDelete.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.BulkOperations.Tests.Issues.WrongAliassesIssue;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/Other.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/Other.cs
index 1079e65262..c5095c1d57 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/Other.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/Other.cs
@@ -4,10 +4,6 @@
 // Created by: Alexander Ovchinnikov
 // Created:    2012.02.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using TestCommon.Model;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/ReferenceFields.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/ReferenceFields.cs
index 9e8d74df75..c0357561f6 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/ReferenceFields.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/ReferenceFields.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using TestCommon.Model;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations.Tests/Structures.cs b/Extensions/Xtensive.Orm.BulkOperations.Tests/Structures.cs
index 59aacb1b58..9ec7e15cc6 100644
--- a/Extensions/Xtensive.Orm.BulkOperations.Tests/Structures.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations.Tests/Structures.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using TestCommon.Model;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations/BulkExtensions.cs b/Extensions/Xtensive.Orm.BulkOperations/BulkExtensions.cs
index 599412cd3f..8bc74c63f8 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/BulkExtensions.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/BulkExtensions.cs
@@ -2,12 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Diagnostics.Contracts;
-using System.Linq;
 using System.Linq.Expressions;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.BulkOperations
 {
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/AddValueContext.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/AddValueContext.cs
index a31faed2e6..e08d356fa6 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/AddValueContext.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/AddValueContext.cs
@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Linq;
 using Xtensive.Orm.Model;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/BaseSqlVisitor.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/BaseSqlVisitor.cs
index 48563d6d8b..f41ca38ebc 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/BaseSqlVisitor.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/BaseSqlVisitor.cs
@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkDeleteOperation.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkDeleteOperation.cs
index e41f13ceaf..7f91c51b56 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkDeleteOperation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkDeleteOperation.cs
@@ -2,10 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Services;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkUpdateOperation.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkUpdateOperation.cs
index e2cc668a01..0d53723117 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkUpdateOperation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/BulkUpdateOperation.cs
@@ -2,13 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Services;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionExtensions.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionExtensions.cs
index ad73adf956..eb83b51994 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionExtensions.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionExtensions.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Linq;
 using Xtensive.Reflection;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionVisitor.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionVisitor.cs
index 273febeff0..5f4439fecc 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionVisitor.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/ExpressionVisitor.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq.Expressions;
 using Xtensive.Core;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/InsertOperation.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/InsertOperation.cs
index e48f5da538..b574d7a055 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/InsertOperation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/InsertOperation.cs
@@ -2,12 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Services;
 using Xtensive.Sql;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/Operation.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/Operation.cs
index 168ed0d643..23e8d36643 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/Operation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/Operation.cs
@@ -2,11 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Providers;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/QueryOperation.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/QueryOperation.cs
index b295a17517..147f796648 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/QueryOperation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/QueryOperation.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/SetOperation.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/SetOperation.cs
index 806a6dcb7d..6492d076a9 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/SetOperation.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/SetOperation.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Services;
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/SetStatement.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/SetStatement.cs
index e53a7fd127..62935a9e29 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/SetStatement.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/SetStatement.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Collections.Generic;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/Updatable.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/Updatable.cs
index 9b417bb184..56a7063f5a 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/Updatable.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/Updatable.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 
 namespace Xtensive.Orm.BulkOperations
diff --git a/Extensions/Xtensive.Orm.BulkOperations/Internals/WellKnownMembers.cs b/Extensions/Xtensive.Orm.BulkOperations/Internals/WellKnownMembers.cs
index 67dc690d4b..740fde85a3 100644
--- a/Extensions/Xtensive.Orm.BulkOperations/Internals/WellKnownMembers.cs
+++ b/Extensions/Xtensive.Orm.BulkOperations/Internals/WellKnownMembers.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Orm.Services;
 
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/AccessToLocalizationOnUpgrade.cs b/Extensions/Xtensive.Orm.Localization.Tests/AccessToLocalizationOnUpgrade.cs
index 708d7d83f3..59d589074f 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/AccessToLocalizationOnUpgrade.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/AccessToLocalizationOnUpgrade.cs
@@ -1,5 +1,4 @@
 using System.Globalization;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Localization.Tests.Model;
 using Xtensive.Orm.Upgrade;
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/CurrentThreadTest.cs b/Extensions/Xtensive.Orm.Localization.Tests/CurrentThreadTest.cs
index 40ceb291dd..5f927103ad 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/CurrentThreadTest.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/CurrentThreadTest.cs
@@ -1,5 +1,3 @@
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Localization.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/DirectEditTest.cs b/Extensions/Xtensive.Orm.Localization.Tests/DirectEditTest.cs
index a3a4415841..ab4298eb23 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/DirectEditTest.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/DirectEditTest.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Localization.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/LocalizationScopeTest.cs b/Extensions/Xtensive.Orm.Localization.Tests/LocalizationScopeTest.cs
index de7d6793e0..fcb3b50881 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/LocalizationScopeTest.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/LocalizationScopeTest.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Localization.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/Model/Page.cs b/Extensions/Xtensive.Orm.Localization.Tests/Model/Page.cs
index b6c774f609..7e51e7e8a3 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/Model/Page.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/Model/Page.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.27
 
-using System;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Localization.Tests.Model
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/Model/PageLocalization.cs b/Extensions/Xtensive.Orm.Localization.Tests/Model/PageLocalization.cs
index a4c51e3c13..0d5d58a607 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/Model/PageLocalization.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/Model/PageLocalization.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.27
 
-using System;
 using System.Globalization;
 using Xtensive.Orm;
 
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/MultipleNodesTest.cs b/Extensions/Xtensive.Orm.Localization.Tests/MultipleNodesTest.cs
index a5096e4b28..cf36f53180 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/MultipleNodesTest.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/MultipleNodesTest.cs
@@ -5,7 +5,6 @@
 // Created:    2019.12.04
 
 using NUnit.Framework;
-using System.Collections.Generic;
 using System.Globalization;
 using TestCommon;
 using Xtensive.Orm.Configuration;
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/ProjectionToCustomTypesTests.cs b/Extensions/Xtensive.Orm.Localization.Tests/ProjectionToCustomTypesTests.cs
index c4f94113de..d8ef3655c8 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/ProjectionToCustomTypesTests.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/ProjectionToCustomTypesTests.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Localization.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Localization.Tests/QueryTests.cs b/Extensions/Xtensive.Orm.Localization.Tests/QueryTests.cs
index e298ff92a5..7f1940b4cd 100644
--- a/Extensions/Xtensive.Orm.Localization.Tests/QueryTests.cs
+++ b/Extensions/Xtensive.Orm.Localization.Tests/QueryTests.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Localization.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Localization/Configuration/Elements/ConfigurationSection.cs b/Extensions/Xtensive.Orm.Localization/Configuration/Elements/ConfigurationSection.cs
index c13ec91716..4ca10b7eaf 100644
--- a/Extensions/Xtensive.Orm.Localization/Configuration/Elements/ConfigurationSection.cs
+++ b/Extensions/Xtensive.Orm.Localization/Configuration/Elements/ConfigurationSection.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2012.07.06
 
-using System;
 using System.Configuration;
 
 namespace Xtensive.Orm.Localization.Configuration
diff --git a/Extensions/Xtensive.Orm.Localization/Configuration/LocalizationConfiguration.cs b/Extensions/Xtensive.Orm.Localization/Configuration/LocalizationConfiguration.cs
index aab701d997..97d7868e0e 100644
--- a/Extensions/Xtensive.Orm.Localization/Configuration/LocalizationConfiguration.cs
+++ b/Extensions/Xtensive.Orm.Localization/Configuration/LocalizationConfiguration.cs
@@ -4,10 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2012.07.06
 
-using System;
 using System.Configuration;
 using System.Globalization;
-using System.Threading;
 
 namespace Xtensive.Orm.Localization.Configuration
 {
diff --git a/Extensions/Xtensive.Orm.Localization/Internals/LocalizationExpressionBuilder.cs b/Extensions/Xtensive.Orm.Localization/Internals/LocalizationExpressionBuilder.cs
index 5602eb4901..4644a236d6 100644
--- a/Extensions/Xtensive.Orm.Localization/Internals/LocalizationExpressionBuilder.cs
+++ b/Extensions/Xtensive.Orm.Localization/Internals/LocalizationExpressionBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.28
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 
diff --git a/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationInfo.cs b/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationInfo.cs
index 2b57991ce9..d2fa799cb5 100644
--- a/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationInfo.cs
+++ b/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.28
 
-using System;
 using System.Reflection;
 using Xtensive.Orm.Model;
 using TypeInfo = Xtensive.Orm.Model.TypeInfo;
diff --git a/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationMap.cs b/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationMap.cs
index 51e17ff140..14a1ac13fe 100644
--- a/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationMap.cs
+++ b/Extensions/Xtensive.Orm.Localization/Internals/TypeLocalizationMap.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.28
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Localization.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm;
diff --git a/Extensions/Xtensive.Orm.Localization/Localization.cs b/Extensions/Xtensive.Orm.Localization/Localization.cs
index 8fdbc9757e..c978257012 100644
--- a/Extensions/Xtensive.Orm.Localization/Localization.cs
+++ b/Extensions/Xtensive.Orm.Localization/Localization.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.27
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Orm.Localization
diff --git a/Extensions/Xtensive.Orm.Localization/LocalizationContext.cs b/Extensions/Xtensive.Orm.Localization/LocalizationContext.cs
index 6944a8b210..285adb86a7 100644
--- a/Extensions/Xtensive.Orm.Localization/LocalizationContext.cs
+++ b/Extensions/Xtensive.Orm.Localization/LocalizationContext.cs
@@ -4,9 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.30
 
-using System;
 using System.Globalization;
-using System.Threading;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Localization
diff --git a/Extensions/Xtensive.Orm.Localization/LocalizationPolicy.cs b/Extensions/Xtensive.Orm.Localization/LocalizationPolicy.cs
index e56f46984c..b5b3c21611 100644
--- a/Extensions/Xtensive.Orm.Localization/LocalizationPolicy.cs
+++ b/Extensions/Xtensive.Orm.Localization/LocalizationPolicy.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.30
 
-using System;
 
 namespace Xtensive.Orm.Localization
 {
diff --git a/Extensions/Xtensive.Orm.Localization/LocalizationSet.cs b/Extensions/Xtensive.Orm.Localization/LocalizationSet.cs
index d2ec63120a..a5931f2bf9 100644
--- a/Extensions/Xtensive.Orm.Localization/LocalizationSet.cs
+++ b/Extensions/Xtensive.Orm.Localization/LocalizationSet.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.30
 
-using System;
 using System.Globalization;
 using Xtensive.Orm.Model;
 
diff --git a/Extensions/Xtensive.Orm.Localization/QueryExtensions.cs b/Extensions/Xtensive.Orm.Localization/QueryExtensions.cs
index f76b33bcdc..fd63fc82c0 100644
--- a/Extensions/Xtensive.Orm.Localization/QueryExtensions.cs
+++ b/Extensions/Xtensive.Orm.Localization/QueryExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.16
 
-using System.Linq;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Localization
diff --git a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Context.cs b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Context.cs
index 207d16cbf2..8b8d4b0ea0 100644
--- a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Context.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Context.cs
@@ -2,10 +2,6 @@
 // ReSharper disable ReturnValueOfPureMethodIsNotUsed
 // ReSharper disable AccessToModifiedClosure
 
-using System;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Transactions;
 using NUnit.Framework;
 using TestCommon.Model;
diff --git a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/DeadlockReprocessing.cs b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/DeadlockReprocessing.cs
index f0f186c873..32d99a3fda 100644
--- a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/DeadlockReprocessing.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/DeadlockReprocessing.cs
@@ -2,10 +2,6 @@
 // ReSharper disable ReturnValueOfPureMethodIsNotUsed
 // ReSharper disable AccessToModifiedClosure
 
-using System;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Transactions;
 using NUnit.Framework;
 using TestCommon.Model;
diff --git a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Other.cs b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Other.cs
index 79dfb0e75f..0e5cc359d5 100644
--- a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Other.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/Other.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using System.Transactions;
 using NUnit.Framework;
 using TestCommon.Model;
diff --git a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/UniqueConstraintViolationReprocessing.cs b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/UniqueConstraintViolationReprocessing.cs
index c901fa1812..2c7f581c4f 100644
--- a/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/UniqueConstraintViolationReprocessing.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing.Tests/Tests/UniqueConstraintViolationReprocessing.cs
@@ -2,8 +2,6 @@
 // ReSharper disable ReturnValueOfPureMethodIsNotUsed
 // ReSharper disable AccessToModifiedClosure
 
-using System;
-using System.Threading;
 using System.Transactions;
 using NUnit.Framework;
 using TestCommon.Model;
diff --git a/Extensions/Xtensive.Orm.Reprocessing/Configuration/ConfigurationSection.cs b/Extensions/Xtensive.Orm.Reprocessing/Configuration/ConfigurationSection.cs
index d93d13802c..23830ebcb5 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/Configuration/ConfigurationSection.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/Configuration/ConfigurationSection.cs
@@ -1,4 +1,3 @@
-using System;
 using System.ComponentModel;
 using System.Configuration;
 
diff --git a/Extensions/Xtensive.Orm.Reprocessing/Configuration/ReprocessingConfiguration.cs b/Extensions/Xtensive.Orm.Reprocessing/Configuration/ReprocessingConfiguration.cs
index 12b6ec5612..7e536b29e1 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/Configuration/ReprocessingConfiguration.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/Configuration/ReprocessingConfiguration.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Configuration;
 using Xtensive.Core;
 
diff --git a/Extensions/Xtensive.Orm.Reprocessing/DomainBuildErrorEventArgs.cs b/Extensions/Xtensive.Orm.Reprocessing/DomainBuildErrorEventArgs.cs
index 99e0acb2bc..f479b1e596 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/DomainBuildErrorEventArgs.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/DomainBuildErrorEventArgs.cs
@@ -1,7 +1,6 @@
 // Copyright (C) 2012-2022 Xtensive LLC.
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
-using System;
 
 namespace Xtensive.Orm.Reprocessing
 {
diff --git a/Extensions/Xtensive.Orm.Reprocessing/DomainBuilder.cs b/Extensions/Xtensive.Orm.Reprocessing/DomainBuilder.cs
index db59efe07a..355aae76e8 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/DomainBuilder.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/DomainBuilder.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Orm.Configuration;
 
diff --git a/Extensions/Xtensive.Orm.Reprocessing/DomainExtensions.cs b/Extensions/Xtensive.Orm.Reprocessing/DomainExtensions.cs
index 5e50e81184..8ce5d15887 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/DomainExtensions.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/DomainExtensions.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Transactions;
 using Xtensive.Orm.Reprocessing.Configuration;
 
diff --git a/Extensions/Xtensive.Orm.Reprocessing/ExecuteActionStrategy.cs b/Extensions/Xtensive.Orm.Reprocessing/ExecuteActionStrategy.cs
index bc1a68f303..05f15041c4 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/ExecuteActionStrategy.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/ExecuteActionStrategy.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Concurrent;
 using System.Transactions;
 using Xtensive.Core;
diff --git a/Extensions/Xtensive.Orm.Reprocessing/ExecuteErrorEventArgs.cs b/Extensions/Xtensive.Orm.Reprocessing/ExecuteErrorEventArgs.cs
index 38e77a0436..c43754445c 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/ExecuteErrorEventArgs.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/ExecuteErrorEventArgs.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Orm.Reprocessing
 {
diff --git a/Extensions/Xtensive.Orm.Reprocessing/ExecutionContext.cs b/Extensions/Xtensive.Orm.Reprocessing/ExecutionContext.cs
index d7fa7e6319..5a93b75661 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/ExecutionContext.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/ExecutionContext.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Transactions;
 
 namespace Xtensive.Orm.Reprocessing
diff --git a/Extensions/Xtensive.Orm.Reprocessing/IExecuteActionStrategy.cs b/Extensions/Xtensive.Orm.Reprocessing/IExecuteActionStrategy.cs
index ba18032c18..b16433a739 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/IExecuteActionStrategy.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/IExecuteActionStrategy.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Reprocessing
 {
diff --git a/Extensions/Xtensive.Orm.Reprocessing/IExecuteConfiguration.cs b/Extensions/Xtensive.Orm.Reprocessing/IExecuteConfiguration.cs
index 357c83c29d..b302e5d85e 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/IExecuteConfiguration.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/IExecuteConfiguration.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Transactions;
 
 namespace Xtensive.Orm.Reprocessing
diff --git a/Extensions/Xtensive.Orm.Reprocessing/Internals/ExecuteConfiguration.cs b/Extensions/Xtensive.Orm.Reprocessing/Internals/ExecuteConfiguration.cs
index c8c9d1b76a..6229c8cdfc 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/Internals/ExecuteConfiguration.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/Internals/ExecuteConfiguration.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Transactions;
 
 namespace Xtensive.Orm.Reprocessing
diff --git a/Extensions/Xtensive.Orm.Reprocessing/ReprocessAttribute.cs b/Extensions/Xtensive.Orm.Reprocessing/ReprocessAttribute.cs
index 275c53630e..4cab67c5dc 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/ReprocessAttribute.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/ReprocessAttribute.cs
@@ -1,6 +1,5 @@
 #if NOT_IMPLMENETED
 
-using System;
 using System.Transactions;
 using PostSharp.Aspects;
 
diff --git a/Extensions/Xtensive.Orm.Reprocessing/ReprocessableDomainBuilder.cs b/Extensions/Xtensive.Orm.Reprocessing/ReprocessableDomainBuilder.cs
index 803e0e9419..dca4d2ecde 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/ReprocessableDomainBuilder.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/ReprocessableDomainBuilder.cs
@@ -1,4 +1,3 @@
-using System;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Reprocessing
diff --git a/Extensions/Xtensive.Orm.Reprocessing/RollbackTransactionException.cs b/Extensions/Xtensive.Orm.Reprocessing/RollbackTransactionException.cs
index 005520f8c2..37b17caf96 100644
--- a/Extensions/Xtensive.Orm.Reprocessing/RollbackTransactionException.cs
+++ b/Extensions/Xtensive.Orm.Reprocessing/RollbackTransactionException.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Reprocessing
 {
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Model/Branch.cs b/Extensions/Xtensive.Orm.Security.Tests/Model/Branch.cs
index d6b432f4fc..4b757f99fa 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Model/Branch.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Model/Branch.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.26
 
-using System;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Security.Tests.Model
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Model/Employee.cs b/Extensions/Xtensive.Orm.Security.Tests/Model/Employee.cs
index 3f5d8272d8..b688be88ec 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Model/Employee.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Model/Employee.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Security.Tests.Model
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Model/VipCustomer.cs b/Extensions/Xtensive.Orm.Security.Tests/Model/VipCustomer.cs
index 7565ba7b7b..ccd9b25e8e 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Model/VipCustomer.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Model/VipCustomer.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Security.Tests.Model
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Permissions/CustomerPermission.cs b/Extensions/Xtensive.Orm.Security.Tests/Permissions/CustomerPermission.cs
index 4651e7b7ad..6ebecb634b 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Permissions/CustomerPermission.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Permissions/CustomerPermission.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Permissions/VipCustomerPermission.cs b/Extensions/Xtensive.Orm.Security.Tests/Permissions/VipCustomerPermission.cs
index 79b9b28852..ee1bead41c 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Permissions/VipCustomerPermission.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Permissions/VipCustomerPermission.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Roles/AircraftManagerRole.cs b/Extensions/Xtensive.Orm.Security.Tests/Roles/AircraftManagerRole.cs
index 8e6679df81..a1cde6f814 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Roles/AircraftManagerRole.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Roles/AircraftManagerRole.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 using Xtensive.Orm.Security.Tests.Permissions;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Roles/AutomobileManagerRole.cs b/Extensions/Xtensive.Orm.Security.Tests/Roles/AutomobileManagerRole.cs
index 435689741c..805dba96ca 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Roles/AutomobileManagerRole.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Roles/AutomobileManagerRole.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 using Xtensive.Orm.Security.Tests.Permissions;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Roles/BranchOfficeManagerRole.cs b/Extensions/Xtensive.Orm.Security.Tests/Roles/BranchOfficeManagerRole.cs
index b6d91bc22e..ef80cb5697 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Roles/BranchOfficeManagerRole.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Roles/BranchOfficeManagerRole.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.26
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesManagerRole.cs b/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesManagerRole.cs
index 2a65a340a0..db5a19083f 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesManagerRole.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesManagerRole.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 using Xtensive.Orm.Security.Tests.Permissions;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesPersonRole.cs b/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesPersonRole.cs
index 3556bc327a..b36710ba02 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesPersonRole.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Roles/SalesPersonRole.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
 using Xtensive.Orm.Security.Tests.Permissions;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/SecurityTestBase.cs b/Extensions/Xtensive.Orm.Security.Tests/SecurityTestBase.cs
index a8235b2a10..c2a1be9619 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/SecurityTestBase.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/SecurityTestBase.cs
@@ -1,6 +1,5 @@
 using System.Configuration;
 using NUnit.Framework;
-using System;
 using TestCommon;
 using Xtensive.Core;
 using Xtensive.Orm;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Tests/HashingServicesTests.cs b/Extensions/Xtensive.Orm.Security.Tests/Tests/HashingServicesTests.cs
index 7f2506c251..151aa06df6 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Tests/HashingServicesTests.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Tests/HashingServicesTests.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Security.Cryptography;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Tests/ImpersonationContextTests.cs b/Extensions/Xtensive.Orm.Security.Tests/Tests/ImpersonationContextTests.cs
index 76d77d79ad..fe3df43e22 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Tests/ImpersonationContextTests.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Tests/ImpersonationContextTests.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
diff --git a/Extensions/Xtensive.Orm.Security.Tests/Tests/PermissionSetTests.cs b/Extensions/Xtensive.Orm.Security.Tests/Tests/PermissionSetTests.cs
index af4f499fea..80e081ee08 100644
--- a/Extensions/Xtensive.Orm.Security.Tests/Tests/PermissionSetTests.cs
+++ b/Extensions/Xtensive.Orm.Security.Tests/Tests/PermissionSetTests.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.30
 
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Tests.Model;
diff --git a/Extensions/Xtensive.Orm.Security/Configuration/Elements/AuthenticationServiceConfigurationElement.cs b/Extensions/Xtensive.Orm.Security/Configuration/Elements/AuthenticationServiceConfigurationElement.cs
index 86cdf4c051..2cc035169d 100644
--- a/Extensions/Xtensive.Orm.Security/Configuration/Elements/AuthenticationServiceConfigurationElement.cs
+++ b/Extensions/Xtensive.Orm.Security/Configuration/Elements/AuthenticationServiceConfigurationElement.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.07
 
-using System;
 using System.Configuration;
 
 namespace Xtensive.Orm.Security.Configuration
diff --git a/Extensions/Xtensive.Orm.Security/Configuration/Elements/ConfigurationSection.cs b/Extensions/Xtensive.Orm.Security/Configuration/Elements/ConfigurationSection.cs
index ca3fe8cf06..328a2fcc33 100644
--- a/Extensions/Xtensive.Orm.Security/Configuration/Elements/ConfigurationSection.cs
+++ b/Extensions/Xtensive.Orm.Security/Configuration/Elements/ConfigurationSection.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.07
 
-using System;
 using System.Configuration;
 
 namespace Xtensive.Orm.Security.Configuration
diff --git a/Extensions/Xtensive.Orm.Security/Configuration/Elements/HashingServiceConfigurationElement.cs b/Extensions/Xtensive.Orm.Security/Configuration/Elements/HashingServiceConfigurationElement.cs
index 81be992993..13ef4576be 100644
--- a/Extensions/Xtensive.Orm.Security/Configuration/Elements/HashingServiceConfigurationElement.cs
+++ b/Extensions/Xtensive.Orm.Security/Configuration/Elements/HashingServiceConfigurationElement.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.07
 
-using System;
 using System.Configuration;
 
 namespace Xtensive.Orm.Security.Configuration
diff --git a/Extensions/Xtensive.Orm.Security/Configuration/SecurityConfiguration.cs b/Extensions/Xtensive.Orm.Security/Configuration/SecurityConfiguration.cs
index 8346a6497c..ae837f7ce5 100644
--- a/Extensions/Xtensive.Orm.Security/Configuration/SecurityConfiguration.cs
+++ b/Extensions/Xtensive.Orm.Security/Configuration/SecurityConfiguration.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.10
 
-using System;
 using System.Configuration;
 
 namespace Xtensive.Orm.Security.Configuration
diff --git a/Extensions/Xtensive.Orm.Security/Cryptography/GenericHashingService.cs b/Extensions/Xtensive.Orm.Security/Cryptography/GenericHashingService.cs
index ab591590f7..321d3ad9be 100644
--- a/Extensions/Xtensive.Orm.Security/Cryptography/GenericHashingService.cs
+++ b/Extensions/Xtensive.Orm.Security/Cryptography/GenericHashingService.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.10
 
-using System;
-using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
 
diff --git a/Extensions/Xtensive.Orm.Security/Cryptography/PlainHashingService.cs b/Extensions/Xtensive.Orm.Security/Cryptography/PlainHashingService.cs
index db8ccfe314..02da26a17f 100644
--- a/Extensions/Xtensive.Orm.Security/Cryptography/PlainHashingService.cs
+++ b/Extensions/Xtensive.Orm.Security/Cryptography/PlainHashingService.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.22
 
-using System;
 using Xtensive.IoC;
 
 namespace Xtensive.Orm.Security.Cryptography
diff --git a/Extensions/Xtensive.Orm.Security/GenericPrincipal.cs b/Extensions/Xtensive.Orm.Security/GenericPrincipal.cs
index 0fb4b87f2b..b8c139837c 100644
--- a/Extensions/Xtensive.Orm.Security/GenericPrincipal.cs
+++ b/Extensions/Xtensive.Orm.Security/GenericPrincipal.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.22
 
-using System;
 using Xtensive.Orm;
 using Xtensive.Orm.Security.Configuration;
 
diff --git a/Extensions/Xtensive.Orm.Security/ImpersonationContext.cs b/Extensions/Xtensive.Orm.Security/ImpersonationContext.cs
index 2987438f6d..130a3d8815 100644
--- a/Extensions/Xtensive.Orm.Security/ImpersonationContext.cs
+++ b/Extensions/Xtensive.Orm.Security/ImpersonationContext.cs
@@ -1,4 +1,3 @@
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Security
diff --git a/Extensions/Xtensive.Orm.Security/Interfaces/IRole.cs b/Extensions/Xtensive.Orm.Security/Interfaces/IRole.cs
index e0c5937682..f6d57d5a93 100644
--- a/Extensions/Xtensive.Orm.Security/Interfaces/IRole.cs
+++ b/Extensions/Xtensive.Orm.Security/Interfaces/IRole.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.26
 
-using System.Collections.Generic;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Security
diff --git a/Extensions/Xtensive.Orm.Security/Permission.cs b/Extensions/Xtensive.Orm.Security/Permission.cs
index 0766b62910..106b5c3845 100644
--- a/Extensions/Xtensive.Orm.Security/Permission.cs
+++ b/Extensions/Xtensive.Orm.Security/Permission.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.10
 
-using System;
-using System.Linq;
 using Xtensive.Orm;
 
 namespace Xtensive.Orm.Security
diff --git a/Extensions/Xtensive.Orm.Security/PermissionSet.cs b/Extensions/Xtensive.Orm.Security/PermissionSet.cs
index dce583dc1b..026980a06b 100644
--- a/Extensions/Xtensive.Orm.Security/PermissionSet.cs
+++ b/Extensions/Xtensive.Orm.Security/PermissionSet.cs
@@ -1,6 +1,4 @@
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Security
 {
diff --git a/Extensions/Xtensive.Orm.Security/Principal.cs b/Extensions/Xtensive.Orm.Security/Principal.cs
index 5ea0689765..3277e5803b 100644
--- a/Extensions/Xtensive.Orm.Security/Principal.cs
+++ b/Extensions/Xtensive.Orm.Security/Principal.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using System.Security.Principal;
 using Xtensive.Orm.Validation;
 
diff --git a/Extensions/Xtensive.Orm.Security/Role.cs b/Extensions/Xtensive.Orm.Security/Role.cs
index 0d2a25a2f0..faedf8a0e0 100644
--- a/Extensions/Xtensive.Orm.Security/Role.cs
+++ b/Extensions/Xtensive.Orm.Security/Role.cs
@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Orm.Validation;
 
diff --git a/Extensions/Xtensive.Orm.Security/SecureQueryRootBuilder.cs b/Extensions/Xtensive.Orm.Security/SecureQueryRootBuilder.cs
index 4bf8042d42..5f8abff229 100644
--- a/Extensions/Xtensive.Orm.Security/SecureQueryRootBuilder.cs
+++ b/Extensions/Xtensive.Orm.Security/SecureQueryRootBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Linq;
 using Xtensive.Orm;
diff --git a/Extensions/Xtensive.Orm.Security/Services/GenericAuthenticationService.cs b/Extensions/Xtensive.Orm.Security/Services/GenericAuthenticationService.cs
index 719c83ac02..326ed67eb4 100644
--- a/Extensions/Xtensive.Orm.Security/Services/GenericAuthenticationService.cs
+++ b/Extensions/Xtensive.Orm.Security/Services/GenericAuthenticationService.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.03.16
 
-using System;
-using System.Linq;
 using System.Security.Principal;
 using Xtensive.Core;
 using Xtensive.IoC;
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntity.cs b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntity.cs
index 6a7bebe7f3..a97f548cb2 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntity.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntity.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tracking.Tests.Model
 {
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntitySetItem.cs b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntitySetItem.cs
index cc9e97f154..f905f5824b 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntitySetItem.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEntitySetItem.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEnum.cs b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEnum.cs
index 2c684efee6..b8a23d8628 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEnum.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyEnum.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tracking.Tests.Model
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyReferenceProperty.cs b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyReferenceProperty.cs
index 1482804f69..9ee6704e80 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyReferenceProperty.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyReferenceProperty.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyStructure.cs b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyStructure.cs
index e79e66a0c2..21579342a6 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyStructure.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/Model/MyStructure.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/TestHelper.cs b/Extensions/Xtensive.Orm.Tracking.Tests/TestHelper.cs
index f867e3ba3d..49e8066e7d 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/TestHelper.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/TestHelper.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Reflection;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/TrackingMonitorTests.cs b/Extensions/Xtensive.Orm.Tracking.Tests/TrackingMonitorTests.cs
index 5366b8df8b..e5897111ba 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/TrackingMonitorTests.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/TrackingMonitorTests.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2012.05.17
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tracking.Tests.Model;
 
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/TrackingStackFrameTests.cs b/Extensions/Xtensive.Orm.Tracking.Tests/TrackingStackFrameTests.cs
index ea972614a9..bf92a10585 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/TrackingStackFrameTests.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/TrackingStackFrameTests.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tracking;
 using Xtensive.Orm.Tracking.Tests.Model;
diff --git a/Extensions/Xtensive.Orm.Tracking.Tests/TrackingTestBase.cs b/Extensions/Xtensive.Orm.Tracking.Tests/TrackingTestBase.cs
index d2f2ad604d..3c248948f6 100644
--- a/Extensions/Xtensive.Orm.Tracking.Tests/TrackingTestBase.cs
+++ b/Extensions/Xtensive.Orm.Tracking.Tests/TrackingTestBase.cs
@@ -1,5 +1,4 @@
 using NUnit.Framework;
-using System;
 using TestCommon;
 using Xtensive.Core;
 using Xtensive.Orm.Tracking.Tests.Model;
diff --git a/Extensions/Xtensive.Orm.Tracking/Interfaces/IDomainTrackingMonitor.cs b/Extensions/Xtensive.Orm.Tracking/Interfaces/IDomainTrackingMonitor.cs
index fa7d8ff333..0d8e1d550f 100644
--- a/Extensions/Xtensive.Orm.Tracking/Interfaces/IDomainTrackingMonitor.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Interfaces/IDomainTrackingMonitor.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tracking
 {
diff --git a/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingItem.cs b/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingItem.cs
index e8e952bde6..218729d493 100644
--- a/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingItem.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingItem.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Collections.Generic;
 using Xtensive.Tuples;
 
 namespace Xtensive.Orm.Tracking
diff --git a/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingMonitor.cs b/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingMonitor.cs
index 4a3d3fda36..ce6ca6b8d3 100644
--- a/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingMonitor.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Interfaces/ITrackingMonitor.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tracking
 {
diff --git a/Extensions/Xtensive.Orm.Tracking/Internals/DomainTrackingMonitor.cs b/Extensions/Xtensive.Orm.Tracking/Internals/DomainTrackingMonitor.cs
index 3271f983e2..6ed69dc1c4 100644
--- a/Extensions/Xtensive.Orm.Tracking/Internals/DomainTrackingMonitor.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Internals/DomainTrackingMonitor.cs
@@ -1,4 +1,3 @@
-using System;
 using Xtensive.IoC;
 
 namespace Xtensive.Orm.Tracking
diff --git a/Extensions/Xtensive.Orm.Tracking/Internals/SessionTrackingMonitor.cs b/Extensions/Xtensive.Orm.Tracking/Internals/SessionTrackingMonitor.cs
index d75ea2991f..f2d4d0618e 100644
--- a/Extensions/Xtensive.Orm.Tracking/Internals/SessionTrackingMonitor.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Internals/SessionTrackingMonitor.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.IoC;
 using Xtensive.Orm.Services;
 
diff --git a/Extensions/Xtensive.Orm.Tracking/Internals/TrackingItem.cs b/Extensions/Xtensive.Orm.Tracking/Internals/TrackingItem.cs
index f89eb3169d..ed5873d793 100644
--- a/Extensions/Xtensive.Orm.Tracking/Internals/TrackingItem.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Internals/TrackingItem.cs
@@ -4,10 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2012.05.16
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Extensions/Xtensive.Orm.Tracking/Internals/TrackingMonitor.cs b/Extensions/Xtensive.Orm.Tracking/Internals/TrackingMonitor.cs
index 9ff7bc6ff8..5f2dedda58 100644
--- a/Extensions/Xtensive.Orm.Tracking/Internals/TrackingMonitor.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Internals/TrackingMonitor.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tracking
 {
diff --git a/Extensions/Xtensive.Orm.Tracking/Internals/TrackingStackFrame.cs b/Extensions/Xtensive.Orm.Tracking/Internals/TrackingStackFrame.cs
index be2efa7bd7..dad798bed6 100644
--- a/Extensions/Xtensive.Orm.Tracking/Internals/TrackingStackFrame.cs
+++ b/Extensions/Xtensive.Orm.Tracking/Internals/TrackingStackFrame.cs
@@ -5,7 +5,6 @@
 // Created:    2012.05.16
 
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Tracking
diff --git a/Extensions/Xtensive.Orm.Tracking/TrackingCompletedEventArgs.cs b/Extensions/Xtensive.Orm.Tracking/TrackingCompletedEventArgs.cs
index c53101c1d1..6d1da541b6 100644
--- a/Extensions/Xtensive.Orm.Tracking/TrackingCompletedEventArgs.cs
+++ b/Extensions/Xtensive.Orm.Tracking/TrackingCompletedEventArgs.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tracking
 {
diff --git a/Extensions/Xtensive.Orm.Tracking/TrackingItemState.cs b/Extensions/Xtensive.Orm.Tracking/TrackingItemState.cs
index 7fb1fec5d3..d0ce9b939f 100644
--- a/Extensions/Xtensive.Orm.Tracking/TrackingItemState.cs
+++ b/Extensions/Xtensive.Orm.Tracking/TrackingItemState.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2012.05.16
 
-using System;
 
 namespace Xtensive.Orm.Tracking
 {
diff --git a/Extensions/Xtensive.Orm.Web.Tests/ActionFilterTest.cs b/Extensions/Xtensive.Orm.Web.Tests/ActionFilterTest.cs
index 2abff0bed7..9b9f575401 100644
--- a/Extensions/Xtensive.Orm.Web.Tests/ActionFilterTest.cs
+++ b/Extensions/Xtensive.Orm.Web.Tests/ActionFilterTest.cs
@@ -1,13 +1,10 @@
-using System;
 using System.Net;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.TestHost;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.AspNetCore.Mvc;
 using NUnit.Framework;
 using Xtensive.Orm.Web.Tests.Filters;
-using System.Linq;
 using System.Diagnostics.CodeAnalysis;
 
 namespace Xtensive.Orm.Web.Tests.Filters
diff --git a/Extensions/Xtensive.Orm.Web.Tests/MiddlewareTest.cs b/Extensions/Xtensive.Orm.Web.Tests/MiddlewareTest.cs
index f1890b922c..e1ccd212d6 100644
--- a/Extensions/Xtensive.Orm.Web.Tests/MiddlewareTest.cs
+++ b/Extensions/Xtensive.Orm.Web.Tests/MiddlewareTest.cs
@@ -2,9 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Net;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.TestHost;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.DependencyInjection;
@@ -12,7 +10,6 @@
 using NUnit.Framework;
 using Xtensive.Orm.Web.Tests.Middleware;
 using Microsoft.AspNetCore.Builder;
-using System.Linq;
 using System.Diagnostics.CodeAnalysis;
 
 namespace Xtensive.Orm.Web.Tests.Middleware
diff --git a/Extensions/Xtensive.Orm.Web.Tests/WebTestBase.cs b/Extensions/Xtensive.Orm.Web.Tests/WebTestBase.cs
index 8e4bfe491d..af34a7ffe5 100644
--- a/Extensions/Xtensive.Orm.Web.Tests/WebTestBase.cs
+++ b/Extensions/Xtensive.Orm.Web.Tests/WebTestBase.cs
@@ -7,7 +7,6 @@
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.AspNetCore.Builder;
-using System;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
 
diff --git a/Extensions/Xtensive.Orm.Web/Filters/SessionActionFilter.cs b/Extensions/Xtensive.Orm.Web/Filters/SessionActionFilter.cs
index e602d7e40c..38da5b2fa6 100644
--- a/Extensions/Xtensive.Orm.Web/Filters/SessionActionFilter.cs
+++ b/Extensions/Xtensive.Orm.Web/Filters/SessionActionFilter.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Xtensive.Core;
diff --git a/Extensions/Xtensive.Orm.Web/Middleware/OpenSessionMiddleware.cs b/Extensions/Xtensive.Orm.Web/Middleware/OpenSessionMiddleware.cs
index 9434431707..f19f2097af 100644
--- a/Extensions/Xtensive.Orm.Web/Middleware/OpenSessionMiddleware.cs
+++ b/Extensions/Xtensive.Orm.Web/Middleware/OpenSessionMiddleware.cs
@@ -2,9 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Microsoft.AspNetCore.Http;
-using System.Threading.Tasks;
 using System.Runtime.ExceptionServices;
 
 namespace Xtensive.Orm.Web.Middleware
diff --git a/Extensions/Xtensive.Orm.Web/SessionAccessor.cs b/Extensions/Xtensive.Orm.Web/SessionAccessor.cs
index 6f3e64c73c..a363d73b05 100644
--- a/Extensions/Xtensive.Orm.Web/SessionAccessor.cs
+++ b/Extensions/Xtensive.Orm.Web/SessionAccessor.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 using Microsoft.AspNetCore.Http;
 
diff --git a/Extensions/Xtensive.Orm.Web/StartupConfigurationExtensions.cs b/Extensions/Xtensive.Orm.Web/StartupConfigurationExtensions.cs
index 52891c421f..b33bf4cfca 100644
--- a/Extensions/Xtensive.Orm.Web/StartupConfigurationExtensions.cs
+++ b/Extensions/Xtensive.Orm.Web/StartupConfigurationExtensions.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.AspNetCore.Mvc.Filters;
diff --git a/Extensions/Xtensive.Orm.Web/WellKnownTypes.cs b/Extensions/Xtensive.Orm.Web/WellKnownTypes.cs
index 8bd7ff88f4..2fa436bdc3 100644
--- a/Extensions/Xtensive.Orm.Web/WellKnownTypes.cs
+++ b/Extensions/Xtensive.Orm.Web/WellKnownTypes.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Orm.Web.Filters;
 
 namespace Xtensive.Orm.Web
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Connection.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Connection.cs
index eb238b3deb..dbd8a629d7 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Connection.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Connection.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.08
 
-using System;
 using System.Data;
 using System.Data.Common;
 using FirebirdSql.Data.FirebirdClient;
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Constants.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Constants.cs
index f9e4e00693..dc360b8fdd 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Constants.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Constants.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.08
 
-using System;
 
 namespace Xtensive.Sql.Drivers.Firebird
 {
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Driver.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Driver.cs
index ffef452dba..71fd60cec6 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Driver.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.08
 
-using System.Linq;
 using Xtensive.Sql.Info;
 using FirebirdSql.Data.FirebirdClient;
 
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/DriverFactory.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/DriverFactory.cs
index cee9b08bd1..5242915337 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/DriverFactory.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/DriverFactory.cs
@@ -4,11 +4,8 @@
 // Created by: Csaba Beer
 // Created:    2011.01.08
 
-using System;
 using System.Data.Common;
 using System.Text.RegularExpressions;
-using System.Threading;
-using System.Threading.Tasks;
 using FirebirdSql.Data.FirebirdClient;
 using Xtensive.Core;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Resources/Strings.Designer.cs
index 55c1209a20..7a7f9cb021 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Sql.Drivers.Firebird.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Compiler.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Compiler.cs
index 2298b13e5a..6f80c22108 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Compiler.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Compiler.cs
@@ -4,13 +4,10 @@
 // Created by: Csaba Beer
 // Created:    2011.01.17
 
-using System;
-using System.Linq;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
 using Xtensive.Core;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Drivers.Firebird.v2_5
 {
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Driver.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Driver.cs
index f915c31c80..26afbf6b14 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Driver.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.10
 
-using System;
 using Xtensive.Sql.Info;
 using Xtensive.Sql.Compiler;
 
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.Queries.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.Queries.cs
index 5fc48fe696..fee58861cd 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.Queries.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.Queries.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.13
 
-using System;
 
 namespace Xtensive.Sql.Drivers.Firebird.v2_5
 {
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.cs
index 9a6512aba6..c32740ca38 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Extractor.cs
@@ -4,12 +4,8 @@
 // Created by: Csaba Beer
 // Created:    2011.01.13
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Sql.Drivers.Firebird.Resources;
 using Xtensive.Sql.Model;
 using Constraint = Xtensive.Sql.Model.Constraint;
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/ServerInfoProvider.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/ServerInfoProvider.cs
index f3d73c9ab5..d0db880003 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/ServerInfoProvider.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/ServerInfoProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.10
 
-using System;
 using Xtensive.Sql.Info;
 
 namespace Xtensive.Sql.Drivers.Firebird.v2_5
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Translator.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Translator.cs
index 9e6d9b16c3..0f8b1aa9c4 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Translator.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/Translator.cs
@@ -4,9 +4,7 @@
 // Created by: Csaba Beer
 // Created:    2011.01.17
 
-using System.Linq;
 using Xtensive.Sql.Compiler;
-using System;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/TypeMapper.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/TypeMapper.cs
index 6816888c7d..de264f4e23 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v2_5/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Csaba Beer
 // Created:    2011.01.10
 
-using System;
 using System.Data.Common;
 using System.Data;
 
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Compiler.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Compiler.cs
index 749d2f39cc..adfd9acd20 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Compiler.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Compiler.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 
 namespace Xtensive.Sql.Drivers.Firebird.v4_0
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Driver.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Driver.cs
index 20263c375f..d795b688b0 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Driver.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Driver.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Info;
 using Xtensive.Sql.Compiler;
 
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Extractor.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Extractor.cs
index 10e78ce94a..16f800ece1 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Extractor.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/Extractor.cs
@@ -2,13 +2,9 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Drivers.Firebird.Resources;
diff --git a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/TypeMapper.cs b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/TypeMapper.cs
index 3d7388f059..3107dfae68 100644
--- a/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v4_0/TypeMapper.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using System.Numerics;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Manual/Advanced/CustomLinqCompilerTest.cs b/Orm/Xtensive.Orm.Manual/Advanced/CustomLinqCompilerTest.cs
index a5a0d3804f..47b88cbe0e 100644
--- a/Orm/Xtensive.Orm.Manual/Advanced/CustomLinqCompilerTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Advanced/CustomLinqCompilerTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.16
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Manual/Advanced/CustomSqlCompilerTest.cs b/Orm/Xtensive.Orm.Manual/Advanced/CustomSqlCompilerTest.cs
index dc3b631f34..de043a8af5 100644
--- a/Orm/Xtensive.Orm.Manual/Advanced/CustomSqlCompilerTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Advanced/CustomSqlCompilerTest.cs
@@ -4,13 +4,11 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.Linq;
 using Xtensive.Orm.Tests;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
-using System.Linq;
 
 namespace Xtensive.Orm.Manual.Advanced.CustomSqlCompiler
 {
diff --git a/Orm/Xtensive.Orm.Manual/Advanced/JoinsAndSubqueriesTest.cs b/Orm/Xtensive.Orm.Manual/Advanced/JoinsAndSubqueriesTest.cs
index d870e15be2..f01bf72402 100644
--- a/Orm/Xtensive.Orm.Manual/Advanced/JoinsAndSubqueriesTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Advanced/JoinsAndSubqueriesTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.24
 
-using System;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Tests;
 
 namespace Xtensive.Orm.Manual.Advanced.JoinsAndSubqueriesTest
diff --git a/Orm/Xtensive.Orm.Manual/Attributes/AttributesTest.cs b/Orm/Xtensive.Orm.Manual/Attributes/AttributesTest.cs
index 69641ff417..2e85d0711d 100644
--- a/Orm/Xtensive.Orm.Manual/Attributes/AttributesTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Attributes/AttributesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm.Manual/Caching/CalculatedValueCachingTest.cs b/Orm/Xtensive.Orm.Manual/Caching/CalculatedValueCachingTest.cs
index de7fb0978e..e6da82de22 100644
--- a/Orm/Xtensive.Orm.Manual/Caching/CalculatedValueCachingTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Caching/CalculatedValueCachingTest.cs
@@ -4,14 +4,11 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.18
 
-using System;
 using System.Linq.Expressions;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Core;
 using Xtensive.Linq;
-using System.Linq;
 using Xtensive.Orm.Tests;
 
 namespace Xtensive.Orm.Manual.Caching
diff --git a/Orm/Xtensive.Orm.Manual/Concurrency/LockingTest.cs b/Orm/Xtensive.Orm.Manual/Concurrency/LockingTest.cs
index e41781fd2b..a8b5cd841a 100644
--- a/Orm/Xtensive.Orm.Manual/Concurrency/LockingTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Concurrency/LockingTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.11
 
-using System;
-using System.Linq;
-using System.Threading;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Manual/Concurrency/VersionsTest.cs b/Orm/Xtensive.Orm.Manual/Concurrency/VersionsTest.cs
index 2d02b09def..67a2938877 100644
--- a/Orm/Xtensive.Orm.Manual/Concurrency/VersionsTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Concurrency/VersionsTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.11
 
-using System;
-using System.Linq;
-using System.Threading;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Manual/DomainAndSession/DomainAndSessionSample.cs b/Orm/Xtensive.Orm.Manual/DomainAndSession/DomainAndSessionSample.cs
index 3bbb4d37aa..20eb409ab7 100644
--- a/Orm/Xtensive.Orm.Manual/DomainAndSession/DomainAndSessionSample.cs
+++ b/Orm/Xtensive.Orm.Manual/DomainAndSession/DomainAndSessionSample.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.17
 
-using System;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Manual/Entities/TestFixture.cs b/Orm/Xtensive.Orm.Manual/Entities/TestFixture.cs
index c9644a0f28..dcf695a20a 100644
--- a/Orm/Xtensive.Orm.Manual/Entities/TestFixture.cs
+++ b/Orm/Xtensive.Orm.Manual/Entities/TestFixture.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.25
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/EntitySets/EntitySetsTest.cs b/Orm/Xtensive.Orm.Manual/EntitySets/EntitySetsTest.cs
index 46f0be3632..91d4bacd53 100644
--- a/Orm/Xtensive.Orm.Manual/EntitySets/EntitySetsTest.cs
+++ b/Orm/Xtensive.Orm.Manual/EntitySets/EntitySetsTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Manual/FutureQueries/FutureQueriesTest.cs b/Orm/Xtensive.Orm.Manual/FutureQueries/FutureQueriesTest.cs
index 42ed153548..3f85ccb96c 100644
--- a/Orm/Xtensive.Orm.Manual/FutureQueries/FutureQueriesTest.cs
+++ b/Orm/Xtensive.Orm.Manual/FutureQueries/FutureQueriesTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.31
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/Indexes/TestFixture.cs b/Orm/Xtensive.Orm.Manual/Indexes/TestFixture.cs
index 7ccbad81b6..6a856a0601 100644
--- a/Orm/Xtensive.Orm.Manual/Indexes/TestFixture.cs
+++ b/Orm/Xtensive.Orm.Manual/Indexes/TestFixture.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.16
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/Intro/CheatSheetTest.cs b/Orm/Xtensive.Orm.Manual/Intro/CheatSheetTest.cs
index 85be5a14a5..4a8ac91ff5 100644
--- a/Orm/Xtensive.Orm.Manual/Intro/CheatSheetTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Intro/CheatSheetTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.23
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Manual/Intro/HelloWorldTest.cs b/Orm/Xtensive.Orm.Manual/Intro/HelloWorldTest.cs
index 88124da74f..6d8b346dd5 100644
--- a/Orm/Xtensive.Orm.Manual/Intro/HelloWorldTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Intro/HelloWorldTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.23
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Manual/Legacy/CustomKeyGenerators/CustomKeyGeneratorsTest.cs b/Orm/Xtensive.Orm.Manual/Legacy/CustomKeyGenerators/CustomKeyGeneratorsTest.cs
index 92ed2a2cc6..989107cf76 100644
--- a/Orm/Xtensive.Orm.Manual/Legacy/CustomKeyGenerators/CustomKeyGeneratorsTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Legacy/CustomKeyGenerators/CustomKeyGeneratorsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.28
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/ModellingDomain/AuditAndOpenGenericsTest.cs b/Orm/Xtensive.Orm.Manual/ModellingDomain/AuditAndOpenGenericsTest.cs
index 1fae2689ae..22f652ae27 100644
--- a/Orm/Xtensive.Orm.Manual/ModellingDomain/AuditAndOpenGenericsTest.cs
+++ b/Orm/Xtensive.Orm.Manual/ModellingDomain/AuditAndOpenGenericsTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.17
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Building;
diff --git a/Orm/Xtensive.Orm.Manual/ModellingDomain/IndexAttributeTest.cs b/Orm/Xtensive.Orm.Manual/ModellingDomain/IndexAttributeTest.cs
index a2ade42e3e..71f140eb62 100644
--- a/Orm/Xtensive.Orm.Manual/ModellingDomain/IndexAttributeTest.cs
+++ b/Orm/Xtensive.Orm.Manual/ModellingDomain/IndexAttributeTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.17
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Manual/Persistent/TestFixture.cs b/Orm/Xtensive.Orm.Manual/Persistent/TestFixture.cs
index 6abcefa0fb..d0f5532c11 100644
--- a/Orm/Xtensive.Orm.Manual/Persistent/TestFixture.cs
+++ b/Orm/Xtensive.Orm.Manual/Persistent/TestFixture.cs
@@ -5,7 +5,6 @@
 // Created:    2009.06.24
 
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Manual/Prefetch/PrefetchTest.cs b/Orm/Xtensive.Orm.Manual/Prefetch/PrefetchTest.cs
index 21d0d2977f..3af44f0781 100644
--- a/Orm/Xtensive.Orm.Manual/Prefetch/PrefetchTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Prefetch/PrefetchTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.24
 
-using System;
 using NUnit.Framework;
-using System.Linq;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Internals.Prefetch;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Manual/Services/DirectSqlAccessorTest.cs b/Orm/Xtensive.Orm.Manual/Services/DirectSqlAccessorTest.cs
index a5f0daf8fa..79528638cc 100644
--- a/Orm/Xtensive.Orm.Manual/Services/DirectSqlAccessorTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Services/DirectSqlAccessorTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2010.02.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/Services/DirectStateAccessorTest.cs b/Orm/Xtensive.Orm.Manual/Services/DirectStateAccessorTest.cs
index ff6c17d6ed..f7955a45b5 100644
--- a/Orm/Xtensive.Orm.Manual/Services/DirectStateAccessorTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Services/DirectStateAccessorTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2010.02.24
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Services;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/Structures/TestFixture.cs b/Orm/Xtensive.Orm.Manual/Structures/TestFixture.cs
index 615940817c..590f410dd6 100644
--- a/Orm/Xtensive.Orm.Manual/Structures/TestFixture.cs
+++ b/Orm/Xtensive.Orm.Manual/Structures/TestFixture.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.16
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Manual/Transactions/NestedTransactionsTest.cs b/Orm/Xtensive.Orm.Manual/Transactions/NestedTransactionsTest.cs
index 5e26b584ba..bd8ec060f4 100644
--- a/Orm/Xtensive.Orm.Manual/Transactions/NestedTransactionsTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Transactions/NestedTransactionsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.23
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Manual/Transactions/SessionSwitchingTest.cs b/Orm/Xtensive.Orm.Manual/Transactions/SessionSwitchingTest.cs
index 434654b50a..85d049b706 100644
--- a/Orm/Xtensive.Orm.Manual/Transactions/SessionSwitchingTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Transactions/SessionSwitchingTest.cs
@@ -4,11 +4,9 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 
 namespace Xtensive.Orm.Manual.Transactions.SessionSwitching
 {
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_1/Model.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_1/Model.cs
index adcbcee237..dcdaea04d9 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_1/Model.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_1/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.11
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_1
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Model.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Model.cs
index d05c6f9a77..28e525c5b8 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Model.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.11
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_2
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Upgrader.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Upgrader.cs
index 6e1c80a360..f01d81012f 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_2/Upgrader.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.12
 
-using System.Collections.Generic;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_2
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Model.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Model.cs
index 478a26e707..559b938dd6 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Model.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.12
 
-using System;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_3
 {
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Upgrader.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Upgrader.cs
index 9e603ef26e..602d1b1f40 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_3/Upgrader.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.12
 
-using System.Collections.Generic;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_3
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Model.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Model.cs
index ed00ca0278..1ee5756232 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Model.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.19
 
-using System;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_4
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Upgrader.cs b/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Upgrader.cs
index 59ffba0072..89c4fe0f15 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/Model_4/Upgrader.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.19
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Manual.Upgrade.Model_4
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeHandlerEnabler.cs b/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeHandlerEnabler.cs
index 60bb322066..b16d7333af 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeHandlerEnabler.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeHandlerEnabler.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.12
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Manual.Upgrade
diff --git a/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeTest.cs b/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeTest.cs
index 3ae4fe1961..16f4c7151f 100644
--- a/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Manual/Upgrade/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.11.11
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Connection.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Connection.cs
index 4bb26e796f..14239e3dc7 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Connection.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Connection.cs
@@ -7,8 +7,6 @@
 using System.Data;
 using System.Data.Common;
 using System.Security;
-using System.Threading;
-using System.Threading.Tasks;
 using MySql.Data.MySqlClient;
 
 namespace Xtensive.Sql.Drivers.MySql
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Driver.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Driver.cs
index 6b0bfe3643..71f72d4677 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Driver.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
 using System.Runtime.CompilerServices;
 using MySql.Data.MySqlClient;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/DriverFactory.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/DriverFactory.cs
index 8be25beb36..4fd19060d7 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/DriverFactory.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/DriverFactory.cs
@@ -4,12 +4,8 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
 using System.Data.Common;
-using System.Linq;
 using System.Security;
-using System.Threading;
-using System.Threading.Tasks;
 using MySql.Data.MySqlClient;
 using Xtensive.Orm;
 using Xtensive.Sql.Drivers.MySql.Resources;
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Resources/Strings.Designer.cs
index ecde49f5d1..23de84229f 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Sql.Drivers.MySql.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Compiler.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Compiler.cs
index 0a66284582..8d210dd310 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Compiler.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Compiler.cs
@@ -4,13 +4,11 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
 using Xtensive.Core;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Drivers.MySql.v5_0
 {
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Extractor.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Extractor.cs
index 72d5fb55a4..3f8df8183e 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Extractor.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Extractor.cs
@@ -4,12 +4,8 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Sql.Drivers.MySql.Resources;
 using Xtensive.Sql.Model;
 using Index = Xtensive.Sql.Model.Index;
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/ServiceInfoProvider.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/ServiceInfoProvider.cs
index 4169c87298..3a8e0352e7 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/ServiceInfoProvider.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/ServiceInfoProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
 using Xtensive.Sql.Info;
 
 namespace Xtensive.Sql.Drivers.MySql.v5_0
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Translator.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Translator.cs
index 8675b2e563..19296b2a92 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Translator.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/Translator.cs
@@ -4,10 +4,7 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/TypeMapper.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/TypeMapper.cs
index 7100406a74..5016ab571d 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_0/TypeMapper.cs
@@ -4,10 +4,8 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
 using System.Data;
 using System.Data.Common;
-using System.Linq;
 using System.Security;
 
 namespace Xtensive.Sql.Drivers.MySql.v5_0
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Compiler.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Compiler.cs
index eb3f10bde2..205609785d 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Compiler.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Compiler.cs
@@ -4,8 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2013.12.30
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Drivers.MySql.v5_6
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Translator.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Translator.cs
index b61d85ac02..88781a54fa 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Translator.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_6/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2013.12.30
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_7/Translator.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_7/Translator.cs
index 9ea62b6741..38960f6419 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_7/Translator.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v5_7/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2022.02.03
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v8_0/Translator.cs b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v8_0/Translator.cs
index e69cd1edbc..92338a3bcf 100644
--- a/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v8_0/Translator.cs
+++ b/Orm/Xtensive.Orm.MySql/Sql.Drivers.MySql/v8_0/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2022.02.03
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.Oracle/Orm.Providers.Oracle/SqlCompiler.cs b/Orm/Xtensive.Orm.Oracle/Orm.Providers.Oracle/SqlCompiler.cs
index 7026269c63..ed2e000238 100644
--- a/Orm/Xtensive.Orm.Oracle/Orm.Providers.Oracle/SqlCompiler.cs
+++ b/Orm/Xtensive.Orm.Oracle/Orm.Providers.Oracle/SqlCompiler.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.07
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Rse;
 using Xtensive.Orm.Rse.Compilation;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Driver.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Driver.cs
index 14c2440e50..385d4d9c3c 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Driver.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Oracle.ManagedDataAccess.Client;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/DriverFactory.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/DriverFactory.cs
index f01e74c4d0..f570e073f2 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/DriverFactory.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/DriverFactory.cs
@@ -4,11 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.16
 
-using System;
 using System.Data.Common;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Oracle.ManagedDataAccess.Client;
 using Xtensive.Core;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Resources/Strings.Designer.cs
index 4464196c88..8551ac049e 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Sql.Drivers.Oracle.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Compiler.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Compiler.cs
index c1799d2294..6b2db93df0 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Compiler.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Compiler.cs
@@ -4,14 +4,12 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
 using Xtensive.Sql.Drivers.Oracle.Resources;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Drivers.Oracle.v09
 {
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Driver.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Driver.cs
index a6f5004797..a44b8f8b84 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Driver.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Extractor.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Extractor.cs
index 3dd581b8a0..bd0a4d292d 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Extractor.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Extractor.cs
@@ -4,13 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Oracle.ManagedDataAccess.Client;
 using Xtensive.Sql.Model;
 using Xtensive.Sql.Drivers.Oracle.Resources;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/ServerInfoProvider.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/ServerInfoProvider.cs
index 15206f6fbc..bbc7c7ef19 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/ServerInfoProvider.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/ServerInfoProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Oracle.ManagedDataAccess.Client;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Translator.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Translator.cs
index 25bc665d52..fe4b5dc4a5 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Translator.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/TypeMapper.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/TypeMapper.cs
index f50fc821a5..ca53b9b8bf 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v09/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using System.Data;
 using System.Data.Common;
 using Oracle.ManagedDataAccess.Client;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Compiler.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Compiler.cs
index c9f2c54fe6..0d855b2b8e 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Compiler.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Compiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using System.Diagnostics;
 using Xtensive.Sql.Compiler;
 
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Extractor.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Extractor.cs
index 1d7eab5088..cd8c166a57 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Extractor.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Extractor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Drivers.Oracle.v10
 {
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Translator.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Translator.cs
index 50e0d67147..bf5d896efe 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Translator.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Xtensive.Sql.Compiler;
 
 namespace Xtensive.Sql.Drivers.Oracle.v10
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/TypeMapper.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/TypeMapper.cs
index ec93021377..722f721388 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v10/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.18
 
-using System;
 using System.Data.Common;
 using System.Diagnostics;
 using Oracle.ManagedDataAccess.Client;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Compiler.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Compiler.cs
index a06eba02f8..bb8eff8bfe 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Compiler.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Compiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using System.Diagnostics;
 using Xtensive.Sql.Compiler;
 
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Extractor.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Extractor.cs
index 79ae90d7d7..17baa1b982 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Extractor.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Extractor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Drivers.Oracle.v11
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Translator.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Translator.cs
index 67c9a80be7..cf63685889 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Translator.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/TypeMapper.cs b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/TypeMapper.cs
index 61e39d250f..7f507caab7 100644
--- a/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.Oracle/Sql.Drivers.Oracle/v11/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.18
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Sql.Drivers.Oracle.v11
diff --git a/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/DomainHandler.cs b/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/DomainHandler.cs
index 27945b097a..61b3085d76 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/DomainHandler.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/DomainHandler.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.07.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Compilation;
 
diff --git a/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/SqlCompiler.cs b/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/SqlCompiler.cs
index 05e8c584d1..88a64ab364 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/SqlCompiler.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/SqlCompiler.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.27
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Rse;
 using Xtensive.Orm.Rse.Compilation;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Connection.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Connection.cs
index 6d8e8cccf1..0bde524191 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Connection.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Connection.cs
@@ -8,8 +8,6 @@
 using Npgsql;
 using System.Data;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Sql.Drivers.PostgreSql
 {
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Driver.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Driver.cs
index 63d93ce217..3f08201e53 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Driver.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Driver.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.IO;
 using System.Net.Sockets;
 using System.Security;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/DriverFactory.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/DriverFactory.cs
index bf4db22e50..ea7517e391 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/DriverFactory.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/DriverFactory.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using System.Data.Common;
 using System.Security;
-using System.Threading;
-using System.Threading.Tasks;
 using Npgsql;
 using Xtensive.Orm;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/PostgreSqlTypeMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/PostgreSqlTypeMapper.cs
index e41eba8e68..85ccb82110 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/PostgreSqlTypeMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/PostgreSqlTypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.04.09
 
-using System;
 using System.Data.Common;
 using Npgsql;
 using NpgsqlTypes;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Resources/Strings.Designer.cs
index 5e37553930..10c2249b35 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Sql.Drivers.PostgreSql.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Compiler.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Compiler.cs
index aed1c3dee1..8efe2019e8 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Compiler.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Compiler.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.25
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v10_0
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Extractor.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Extractor.cs
index 57412aeb1c..d1910eacff 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Extractor.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Extractor.cs
@@ -4,11 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.25
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Translator.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Translator.cs
index 5abb3f0dcd..7208dbc9e8 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Translator.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v10_0/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.25
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Compiler.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Compiler.cs
index 8b723edd8d..17f50bfefd 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Compiler.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Compiler.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Providers.PostgreSql;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Driver.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Driver.cs
index bf1e7874fd..6eaba6c1bc 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Driver.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using NpgsqlTypes;
 using Xtensive.Reflection.PostgreSql;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Extractor.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Extractor.cs
index 34a0b709a7..5b9e776427 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Extractor.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Extractor.cs
@@ -2,9 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Data.Common;
 using System.Diagnostics;
 using System.Text;
@@ -12,9 +10,6 @@
 using Xtensive.Core;
 using Xtensive.Sql.Model;
 using Xtensive.Sql.Dml;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Index = Xtensive.Sql.Model.Index;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_0
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PathMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PathMapper.cs
index 0ae1f821e4..9eb825d7ff 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PathMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PathMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.04.10
 
-using System;
 using System.Data.Common;
 using Npgsql;
 using NpgsqlTypes;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PolygonMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PolygonMapper.cs
index 6b25c19770..eb6269549f 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PolygonMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/PolygonMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.04.10
 
-using System;
 using System.Data.Common;
 using Npgsql;
 using NpgsqlTypes;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/ServerInfoProvider.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/ServerInfoProvider.cs
index 62c22b5210..81544ff84b 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/ServerInfoProvider.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/ServerInfoProvider.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Info;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_0
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Translator.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Translator.cs
index 322509933e..b54678b3ec 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Translator.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/Translator.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Diagnostics;
 using System.Text;
 using NpgsqlTypes;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/TypeMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/TypeMapper.cs
index 4e419085d3..f372cf6b1b 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_0/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Security;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Driver.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Driver.cs
index 082752b95f..8e6624afa1 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Driver.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using Npgsql;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Translator.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Translator.cs
index 2972235186..2ed3559529 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Translator.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/Translator.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/TypeMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/TypeMapper.cs
index 9be3f94728..c965ced811 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_1/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_1
 {
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Compiler.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Compiler.cs
index 68496eca67..0b063fc1af 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Compiler.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Compiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_2
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Driver.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Driver.cs
index ba36f2e06f..f938597dae 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Driver.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using Npgsql;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Extractor.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Extractor.cs
index 192766a9f2..dff328545c 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Extractor.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Extractor.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Translator.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Translator.cs
index e648b6e2dc..39cbd9087d 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Translator.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/Translator.cs
@@ -7,6 +7,7 @@
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
 using Xtensive.Sql.Compiler;
+using Index = Xtensive.Sql.Model.Index;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_2
 {
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/TypeMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/TypeMapper.cs
index 987922dc29..9f21d9751b 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_2/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_2
 {
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Compiler.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Compiler.cs
index f5c3cabe09..8801b2b790 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Compiler.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Compiler.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Text;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Driver.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Driver.cs
index 603d96536e..ec2cc0b1bb 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Driver.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using Npgsql;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Translator.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Translator.cs
index fb0fe8279e..0ad65c7238 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Translator.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/Translator.cs
@@ -2,13 +2,11 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Text;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
-using System.Linq;
 using Xtensive.Reflection.PostgreSql;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_3
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/TypeMapper.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/TypeMapper.cs
index 41c200e1bb..4837a766c2 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_3/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
 using System.Data;
 using System.Data.Common;
 
diff --git a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_4/Extractor.cs b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_4/Extractor.cs
index 4b7c542466..a5a6bd0b2e 100644
--- a/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_4/Extractor.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/Sql.Drivers.PostgreSql/v8_4/Extractor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Kryuchkov
 // Created:    2009.07.07
 
-using System;
 using System.Data.Common;
 
 namespace Xtensive.Sql.Drivers.PostgreSql.v8_4
diff --git a/Orm/Xtensive.Orm.PostgreSql/WellKnownTypes.cs b/Orm/Xtensive.Orm.PostgreSql/WellKnownTypes.cs
index 58c927fd78..88d19c0c00 100644
--- a/Orm/Xtensive.Orm.PostgreSql/WellKnownTypes.cs
+++ b/Orm/Xtensive.Orm.PostgreSql/WellKnownTypes.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NpgsqlTypes;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/DomainHandler.cs b/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/DomainHandler.cs
index 30a34371e8..7fe84d205e 100644
--- a/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/DomainHandler.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/DomainHandler.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.07.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Compilation;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SearchConditionCompilerV09.cs b/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SearchConditionCompilerV09.cs
index 2f2983fe45..feefba969d 100644
--- a/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SearchConditionCompilerV09.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SearchConditionCompilerV09.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
 using System.Globalization;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm.FullTextSearchCondition;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
diff --git a/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SqlCompiler.cs b/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SqlCompiler.cs
index 3f332d0c47..c769b5e74f 100644
--- a/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SqlCompiler.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Orm.Providers.SqlServer/SqlCompiler.cs
@@ -4,9 +4,6 @@
 // Created by: Vakhtina Elena
 // Created:    2009.02.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Orm.Rse;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Connection.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Connection.cs
index c05853c942..52aa282996 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Connection.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Connection.cs
@@ -4,12 +4,9 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.11
 
-using System;
 using System.Data;
 using System.Data.Common;
 using Microsoft.Data.SqlClient;
-using System.Threading;
-using System.Threading.Tasks;
 using SqlServerConnection = Microsoft.Data.SqlClient.SqlConnection;
 
 namespace Xtensive.Sql.Drivers.SqlServer
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Driver.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Driver.cs
index 1f7eaf56d4..b61d14217c 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Driver.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/Driver.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
-using System.Collections.Generic;
 using Microsoft.Data.SqlClient;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/DriverFactory.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/DriverFactory.cs
index 8cf26837c0..a13b9ffffd 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/DriverFactory.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/DriverFactory.cs
@@ -4,12 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.23
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
 using Microsoft.Data.SqlClient;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm;
 using Xtensive.Sql.Info;
 using Xtensive.SqlServer.Resources;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/ErrorMessageParser.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/ErrorMessageParser.cs
index 1e01db1b51..bfcbb43d7d 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/ErrorMessageParser.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/ErrorMessageParser.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/InternalHelpers.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/InternalHelpers.cs
index bc767a3c27..6a72de07da 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/InternalHelpers.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/InternalHelpers.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.04.10
 
-using System;
 using Microsoft.Data.SqlClient;
 using System.Data.SqlTypes;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/SqlServerTypeMapper.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/SqlServerTypeMapper.cs
index 8ba2389eaa..42bb6ec5de 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/SqlServerTypeMapper.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/SqlServerTypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.07
 
-using System;
 using System.Data.Common;
 using Microsoft.Data.SqlClient;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ColumnResolver.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ColumnResolver.cs
index 61f10b951e..621534de01 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ColumnResolver.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ColumnResolver.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Drivers.SqlServer.v09
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Compiler.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Compiler.cs
index 7c56b6b41b..9325884cdf 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Compiler.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Compiler.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.03.11
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Driver.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Driver.cs
index 4982557a50..f7f1cedfba 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Driver.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Driver.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
 using SqlServerConnection = Microsoft.Data.SqlClient.SqlConnection;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Extractor.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Extractor.cs
index 23d1c940e8..87a5ce20f1 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Extractor.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Extractor.cs
@@ -4,13 +4,9 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.11
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
 using System.Globalization;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Sql.Info;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ServerInfoProvider.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ServerInfoProvider.cs
index f5fe6ad68f..805b11790b 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ServerInfoProvider.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/ServerInfoProvider.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Info;
 using SqlServerConnection = Microsoft.Data.SqlClient.SqlConnection;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Translator.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Translator.cs
index 7f07342b1c..fda7223f43 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Translator.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/Translator.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/TypeMapper.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/TypeMapper.cs
index bdc8e83fd9..0e45853900 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v09/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.02
 
-using System;
 using System.Data;
 using System.Data.Common;
 using Microsoft.Data.SqlClient;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Compiler.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Compiler.cs
index f0ea137bab..efabaf2227 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Compiler.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Compiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.07
 
-using System;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Drivers.SqlServer.v10
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Driver.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Driver.cs
index a8bf56e356..04d52a876f 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Driver.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.07
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/ServerInfoProvider.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/ServerInfoProvider.cs
index c354a85186..a9a97e4178 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/ServerInfoProvider.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/ServerInfoProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Kryuchkov
 // Created:    2009.07.07
 
-using System;
 using Xtensive.Sql.Info;
 using SqlServerConnection = Microsoft.Data.SqlClient.SqlConnection;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Translator.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Translator.cs
index 43bd6ee109..63bd9e177d 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Translator.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.07
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/TypeMapper.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/TypeMapper.cs
index f4424cb1cc..76a1064b33 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v10/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.02
 
-using System;
 using System.Data;
 using System.Data.Common;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Compiler.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Compiler.cs
index b4f91e357b..72712bb44a 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Compiler.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Compiler.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.02
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Extractor.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Extractor.cs
index 950ccb9fec..befa524d52 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Extractor.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Extractor.cs
@@ -4,11 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.05
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Sql.Drivers.SqlServer.v11
 {
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Translator.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Translator.cs
index f9fddc03c4..d87f25e741 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Translator.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v11/Translator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.02
 
-using System;
 using System.Text;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
diff --git a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v13/Driver.cs b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v13/Driver.cs
index feb608a1eb..3b610805cc 100644
--- a/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v13/Driver.cs
+++ b/Orm/Xtensive.Orm.SqlServer/Sql.Drivers.SqlServer/v13/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.09.21
 
-using System.Collections.Generic;
 using Xtensive.Sql.Drivers.SqlServer.v10;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.SqlServer/SqlServer.Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.SqlServer/SqlServer.Resources/Strings.Designer.cs
index 48ff58f17b..be0fd46096 100644
--- a/Orm/Xtensive.Orm.SqlServer/SqlServer.Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.SqlServer/SqlServer.Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.SqlServer.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureCollation.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureCollation.cs
index e6111bf78b..6db5e111dc 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureCollation.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureCollation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
 using System.Data.SQLite;
 
 namespace Xtensive.Sql.Drivers.Sqlite.Collations
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureIgnoreCaseCollation.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureIgnoreCaseCollation.cs
index ac92bee00f..1d5df9d4e7 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureIgnoreCaseCollation.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/CurrentCultureIgnoreCaseCollation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
 using System.Data.SQLite;
 
 namespace Xtensive.Sql.Drivers.Sqlite.Collations
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureCollation.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureCollation.cs
index 60a70bfb53..9333fa6867 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureCollation.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureCollation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
 using System.Data.SQLite;
 
 namespace Xtensive.Sql.Drivers.Sqlite.Collations
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureIgnoreCaseCollation.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureIgnoreCaseCollation.cs
index 9438775c8e..f4510b240b 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureIgnoreCaseCollation.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/InvariantCultureIgnoreCaseCollation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
 using System.Data.SQLite;
 
 namespace Xtensive.Sql.Drivers.Sqlite.Collations
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalCollation.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalCollation.cs
index e8debc0e8b..62595746f1 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalCollation.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalCollation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
 using System.Data.SQLite;
 
 namespace Xtensive.Sql.Drivers.Sqlite.Collations
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalIgnoreCaseCollation.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalIgnoreCaseCollation.cs
index c4cfb09cca..4144d3d9db 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalIgnoreCaseCollation.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Collations/OrdinalIgnoreCaseCollation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
 using System.Data.SQLite;
 
 namespace Xtensive.Sql.Drivers.Sqlite.Collations
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Connection.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Connection.cs
index ce9cfb2835..69484e7d6f 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Connection.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Connection.cs
@@ -8,8 +8,6 @@
 using System.Data.Common;
 using System.Data.SQLite;
 using System.Security;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Sql.Drivers.Sqlite
 {
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Driver.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Driver.cs
index 32fd6bdeaf..94d2abac1b 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Driver.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
 using System.Data.SQLite;
 using System.Security;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/DriverFactory.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/DriverFactory.cs
index 7c152a1df3..0f6cd4578f 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/DriverFactory.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/DriverFactory.cs
@@ -4,12 +4,9 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
 using System.Data.Common;
 using System.Data.SQLite;
 using System.Text.RegularExpressions;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm;
 using Xtensive.Sql.Drivers.Sqlite.Resources;
 using Xtensive.Sql.Drivers.Sqlite.v3;
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/ProviderInitializer.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/ProviderInitializer.cs
index 7f528311ff..43694debe1 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/ProviderInitializer.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/ProviderInitializer.cs
@@ -4,13 +4,10 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.08.21
 
-using System;
 using System.Data.SQLite;
 using System.IO;
-using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
-using System.Threading;
 using Xtensive.Core;
 using Xtensive.Sql.Drivers.Sqlite.Resources;
 
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Resources/Strings.Designer.cs
index 534561a42d..69c620ba06 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Sql.Drivers.Sqlite.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Compiler.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Compiler.cs
index dc044373f7..12d9cee7e6 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Compiler.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Compiler.cs
@@ -4,9 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Driver.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Driver.cs
index 1da2c1cd03..5f6b68ba96 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Driver.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Driver.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Extractor.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Extractor.cs
index 3d7b0c1921..9af649a452 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Extractor.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Extractor.cs
@@ -4,14 +4,9 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
 using System.Globalization;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Sql.Model;
 using Index = Xtensive.Sql.Model.Index;
 
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/ServerInfoProvider.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/ServerInfoProvider.cs
index ffc460b5ab..c20633d4ed 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/ServerInfoProvider.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/ServerInfoProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
 using Xtensive.Sql.Info;
 
 namespace Xtensive.Sql.Drivers.Sqlite.v3
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Translator.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Translator.cs
index de11b35025..19b7cd4b64 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Translator.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/Translator.cs
@@ -4,9 +4,7 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
 using System.Text;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Ddl;
diff --git a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/TypeMapper.cs b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/TypeMapper.cs
index eb1ec7f574..6ebd1a1341 100644
--- a/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/TypeMapper.cs
+++ b/Orm/Xtensive.Orm.Sqlite/Sql.Drivers.Sqlite/v3/TypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.04.29
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Data.SQLite;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Arithmetics/AritmeticsTest.cs b/Orm/Xtensive.Orm.Tests.Core/Arithmetics/AritmeticsTest.cs
index d0144f08bb..f9519f1689 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Arithmetics/AritmeticsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Arithmetics/AritmeticsTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.22
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Arithmetic;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Caching/CachePerformanceTest.cs b/Orm/Xtensive.Orm.Tests.Core/Caching/CachePerformanceTest.cs
index ffba35c3ef..e6ae3a7f37 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Caching/CachePerformanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Caching/CachePerformanceTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.09.27
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Caching;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Caching/FastConcurrentLruCacheTest.cs b/Orm/Xtensive.Orm.Tests.Core/Caching/FastConcurrentLruCacheTest.cs
index 73da0a731c..4c5bd7e52d 100755
--- a/Orm/Xtensive.Orm.Tests.Core/Caching/FastConcurrentLruCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Caching/FastConcurrentLruCacheTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Conversion;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Caching/InfiniteCacheTest.cs b/Orm/Xtensive.Orm.Tests.Core/Caching/InfiniteCacheTest.cs
index 3a364b2aa1..b19f13482b 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Caching/InfiniteCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Caching/InfiniteCacheTest.cs
@@ -4,9 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.11
 
-using System;
 using System.Diagnostics;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Caching/LruCacheTest.cs b/Orm/Xtensive.Orm.Tests.Core/Caching/LruCacheTest.cs
index f8587b36af..e57fab5af6 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Caching/LruCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Caching/LruCacheTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Conversion;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Caching/WeakCacheTest.cs b/Orm/Xtensive.Orm.Tests.Core/Caching/WeakCacheTest.cs
index cacb970545..b8eab8249d 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Caching/WeakCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Caching/WeakCacheTest.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Caching/WeakestCacheTest.cs b/Orm/Xtensive.Orm.Tests.Core/Caching/WeakestCacheTest.cs
index e1f1e3c27c..10483c31a3 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Caching/WeakestCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Caching/WeakestCacheTest.cs
@@ -4,12 +4,9 @@
 // Created by: Alex Yakunin
 // Created:    2008.09.29
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Caching;
-using System.Linq;
 using Xtensive.Orm.Tests;
 
 namespace Xtensive.Orm.Tests.Core.Caching
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/ChainedBufferTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/ChainedBufferTest.cs
index 914dd9f98d..7d17fdb42a 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/ChainedBufferTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/ChainedBufferTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alena Mikshina
 // Created:    2013.08.19
 
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/CollectionUtilsTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/CollectionUtilsTest.cs
index 9171f96396..e36e600747 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/CollectionUtilsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/CollectionUtilsTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2019.03.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/EnumerableExtensionsTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/EnumerableExtensionsTest.cs
index 7b16f3b2e2..7e4d04a425 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/EnumerableExtensionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/EnumerableExtensionsTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/ExtensionCollectionTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/ExtensionCollectionTest.cs
index f10d690884..0e2caec6fe 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/ExtensionCollectionTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/ExtensionCollectionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.03
 
-using System;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/FlagCollectionTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/FlagCollectionTest.cs
index 312842ed58..10871a6c38 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/FlagCollectionTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/FlagCollectionTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.10.01
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Conversion;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/LinkedListTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/LinkedListTest.cs
index ef6d57429d..e24bee8f92 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/LinkedListTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/LinkedListTest.cs
@@ -4,11 +4,9 @@
 // Created by: Alexis Kochetov
 // Created:    2011.01.17
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Collections;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Core.Collections
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/NativeTypeClassifierTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/NativeTypeClassifierTest.cs
index f1bea28ca8..e8a6a79798 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/NativeTypeClassifierTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/NativeTypeClassifierTest.cs
@@ -4,14 +4,11 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.02
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Orm.Tests;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Core.Collections
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Collections/TopologicalSorterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Collections/TopologicalSorterTest.cs
index 74a37fa23e..7ed4ea8067 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Collections/TopologicalSorterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Collections/TopologicalSorterTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTestModel.cs b/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTestModel.cs
index f0eb32652d..f01967e349 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTestModel.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTestModel.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.17
 
-using System;
 using Xtensive.Comparison;
 
 namespace Xtensive.Orm.Tests.Core.Comparison
diff --git a/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTests.cs b/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTests.cs
index ceb9ff2592..b4ea666062 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Comparison/ComparerProviderTests.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.17
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Comparison/EqualityComparerProviderTests.cs b/Orm/Xtensive.Orm.Tests.Core/Comparison/EqualityComparerProviderTests.cs
index c4c7f8b373..d94b154bf3 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Comparison/EqualityComparerProviderTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Comparison/EqualityComparerProviderTests.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.17
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Comparison/StringComparisonTest.cs b/Orm/Xtensive.Orm.Tests.Core/Comparison/StringComparisonTest.cs
index caa220f3a3..598f338ba6 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Comparison/StringComparisonTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Comparison/StringComparisonTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.08
 
-using System;
 using System.Globalization;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/ConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/ConverterTest.cs
index 840fb8cf4b..9c5ac82bfe 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/ConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/ConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.10.03
 
-using System;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Conversion;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/BooleanConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/BooleanConverterTest.cs
index a4627d588f..4d1266b695 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/BooleanConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/BooleanConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ByteConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ByteConverterTest.cs
index 4f0a6b3c9d..584ac8946e 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ByteConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ByteConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/CharConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/CharConverterTest.cs
index 8a6467cb1b..20128955f9 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/CharConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/CharConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.28
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ConverterTestBase.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ConverterTestBase.cs
index 7db63314ab..8e04f87440 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ConverterTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/ConverterTestBase.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.25
 
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DateTimeConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DateTimeConverterTest.cs
index a39cb6cd90..4a681ba448 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DateTimeConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DateTimeConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using System.Globalization;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DecimalConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DecimalConverterTest.cs
index 87cec752b4..4cbed058ea 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DecimalConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DecimalConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DoubleConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DoubleConverterTest.cs
index f0981b78a0..e4ab677194 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DoubleConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/DoubleConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/GuidConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/GuidConverterTest.cs
index fe65a29422..3adb6aff27 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/GuidConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/GuidConverterTest.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.25
 
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int16ConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int16ConverterTest.cs
index 6638568a76..14989e8761 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int16ConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int16ConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int32ConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int32ConverterTest.cs
index 5ba19cc727..5318de0fae 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int32ConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int32ConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int64ConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int64ConverterTest.cs
index 94b3672ac9..351e070731 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int64ConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/Int64ConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SByteConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SByteConverterTest.cs
index 63f6a048af..5a2165f548 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SByteConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SByteConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SingleConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SingleConverterTest.cs
index 8b2fc6a2aa..9b7e976db3 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SingleConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/SingleConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringAdvancedConverter.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringAdvancedConverter.cs
index 286e415186..fed15d4dba 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 using Xtensive.Conversion;
 
 namespace Xtensive.Orm.Tests.Core.Conversion
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringConverterTest.cs
index b9403634e8..a39c6b5f90 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/StringConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.26
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TestConverterProvider.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TestConverterProvider.cs
index b22328aefc..31b908f047 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TestConverterProvider.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TestConverterProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 using Xtensive.Conversion;
 
 namespace Xtensive.Orm.Tests.Core.Conversion
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TimeSpanConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TimeSpanConverterTest.cs
index fa8f8ce847..170706176e 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TimeSpanConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/TimeSpanConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.11.12
 
-using System;
 using System.Globalization;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt16ConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt16ConverterTest.cs
index 9a10e2af4c..5b93d965c4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt16ConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt16ConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt32converterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt32converterTest.cs
index 7573abf531..d6c4a8cb38 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt32converterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt32converterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt64ConverterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt64ConverterTest.cs
index c83e401999..d39a2b98e0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt64ConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Conversion/Internals/UInt64ConverterTest.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Conversion;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/DebugInfoTest.cs b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/DebugInfoTest.cs
index 6a1ae909e5..7570bf21c9 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/DebugInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/DebugInfoTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Core.Diagnostics
diff --git a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/LogMessageTest.cs b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/LogMessageTest.cs
index 9e6520e15d..cb64e5e342 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/LogMessageTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/LogMessageTest.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    17.06.2008
 
-using System;
 using System.Globalization;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/MeasurementTest.cs b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/MeasurementTest.cs
index 8f426b9a87..3413fbe668 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/MeasurementTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/MeasurementTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/RuntimeInfoTest.cs b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/RuntimeInfoTest.cs
index e825babfc3..d2f09ae6ff 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Diagnostics/RuntimeInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Diagnostics/RuntimeInfoTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Core.Diagnostics
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/AllocationTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/AllocationTest.cs
index 3a4dacdac0..f921bc7a7d 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/AllocationTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/AllocationTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.04.17
 
-using System;
 using System.Runtime.Serialization;
 using NUnit.Framework;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CallTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CallTest.cs
index 5526bff77d..325c1736ea 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CallTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CallTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.29
 
-using System;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CastTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CastTest.cs
index 37bef44b01..8ec23a7540 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CastTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CastTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.11.21
 
-using System;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Core.DotNetFramework
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CloningTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CloningTest.cs
index 0db3920df0..efd1985b77 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CloningTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CloningTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.24
 
-using System;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Logging;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CoreFeaturesTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CoreFeaturesTest.cs
index 9a9239f748..36c26854ba 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CoreFeaturesTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/CoreFeaturesTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.04.17
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/FieldTypeTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/FieldTypeTest.cs
index 98676216fe..d9dea93150 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/FieldTypeTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/FieldTypeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.09.01
 
-using System;
-using System.Threading;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Core.DotNetFramework
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/GenericFeaturesTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/GenericFeaturesTest.cs
index 2c00a66822..6f92844e7e 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/GenericFeaturesTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/GenericFeaturesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.24
 
-using System;
 using NUnit.Framework;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/InterfaceTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/InterfaceTest.cs
index cb3ae6ab5d..f82fd63f05 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/InterfaceTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/InterfaceTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.01
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/MemoryAccessTypeTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/MemoryAccessTypeTest.cs
index 4e7727b64e..e7af7cb1fa 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/MemoryAccessTypeTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/MemoryAccessTypeTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.04.17
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/NewTupleLogicTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/NewTupleLogicTest.cs
index 74db2645c4..1a705991e7 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/NewTupleLogicTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/NewTupleLogicTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.09.02
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/PointersTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/PointersTest.cs
index 073ba0b42e..fe334849f8 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/PointersTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/PointersTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.05.27
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Logging;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/StaticMethodTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/StaticMethodTest.cs
index 817928f470..72502d2d95 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/StaticMethodTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/StaticMethodTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.16
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/SwitchVsArrayTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/SwitchVsArrayTest.cs
index a4447c63ea..68248e4aa3 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/SwitchVsArrayTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/SwitchVsArrayTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.15
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ThreadingTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ThreadingTest.cs
index 18f04de9a8..a5c8473711 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ThreadingTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ThreadingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.05.27
 
-using System;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Logging;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ValidationTest.cs b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ValidationTest.cs
index fc00d22110..ba826587d1 100644
--- a/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ValidationTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/DotNetFramework/ValidationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.24
 
-using System;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Logging;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/GlobalTestSetup.cs b/Orm/Xtensive.Orm.Tests.Core/GlobalTestSetup.cs
index 2237b4952e..caa5dd0526 100644
--- a/Orm/Xtensive.Orm.Tests.Core/GlobalTestSetup.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/GlobalTestSetup.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Logging;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Helpers/StringExtensionsTest.cs b/Orm/Xtensive.Orm.Tests.Core/Helpers/StringExtensionsTest.cs
index 20216335a7..d944ca560e 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Helpers/StringExtensionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Helpers/StringExtensionsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.17
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Helpers/TopologicalSorterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Helpers/TopologicalSorterTest.cs
index 379c65a316..a81b7ad13b 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Helpers/TopologicalSorterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Helpers/TopologicalSorterTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests.Core/IoC/MainTest.cs b/Orm/Xtensive.Orm.Tests.Core/IoC/MainTest.cs
index ce85544c22..75b9e17646 100644
--- a/Orm/Xtensive.Orm.Tests.Core/IoC/MainTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/IoC/MainTest.cs
@@ -4,11 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.15
 
-using System;
-using System.Collections.Generic;
 using System.Configuration;
 using System.Diagnostics;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/CachingExpressionCompilerTest.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/CachingExpressionCompilerTest.cs
index f2cb9a7f4c..2349654dea 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/CachingExpressionCompilerTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/CachingExpressionCompilerTest.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.07
 
-using System;
 using System.Collections;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/ConstantExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/ConstantExtractorTest.cs
index 660557bc7f..7744d78f1f 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/ConstantExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/ConstantExtractorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.07
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTestBase.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTestBase.cs
index f22b642f28..d60f48c078 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTestBase.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTreeTest.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTreeTest.cs
index 109f0bd369..4485df6cc1 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTreeTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionTreeTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.07
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionWriterTest.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionWriterTest.cs
index 677e34d634..5beb3b4317 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionWriterTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/ExpressionWriterTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.02.09
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/LambdaExpressionFactoryTests.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/LambdaExpressionFactoryTests.cs
index 5404830387..a0ae8221c4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/LambdaExpressionFactoryTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/LambdaExpressionFactoryTests.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Linq/SerializableExpressionsTest.cs b/Orm/Xtensive.Orm.Tests.Core/Linq/SerializableExpressionsTest.cs
index 3be10691f4..e7deaf406c 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Linq/SerializableExpressionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Linq/SerializableExpressionsTest.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
 using System.IO;
-using System.Linq;
 using System.Runtime.Serialization;
 using System.Runtime.Serialization.Formatters.Binary;
 using System.Runtime.Serialization.Formatters;
@@ -14,7 +12,6 @@
 using Xtensive.Core;
 using Xtensive.Linq;
 using Xtensive.Linq.SerializableExpressions;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests.Core.Linq
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Logging/LogManagerTests.cs b/Orm/Xtensive.Orm.Tests.Core/Logging/LogManagerTests.cs
index 0b1b85b3e8..e5ef2e9f2c 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Logging/LogManagerTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Logging/LogManagerTests.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.10.14
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Logging;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogInstanceTests.cs b/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogInstanceTests.cs
index 2583e31a9e..f9446ca7b2 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogInstanceTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogInstanceTests.cs
@@ -4,10 +4,8 @@
 // Created by: Alexey Kulakov
 // Created:    2013.10.14
 
-using System;
 using System.Diagnostics;
 using System.IO;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Logging;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogTests.cs b/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogTests.cs
index 171623b623..04003b0e8b 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Logging/WriteToLogTests.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2013.10.14
 
-using System;
 using System.IO;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Logging;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DataUpgradeTest.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DataUpgradeTest.cs
index 6ff682ae63..6b98e4de62 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DataUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DataUpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.17
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Database.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Database.cs
index 435b0edc1f..382e521fc0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Database.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Database.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/DatabaseCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/DatabaseCollection.cs
index 1d5d328e7c..f06ec87417 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/DatabaseCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/DatabaseCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Index.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Index.cs
index 84452cc475..8e36846dc0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Index.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Index.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/IndexCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/IndexCollection.cs
index a2052e80d7..becc7cefc9 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/IndexCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/IndexCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeBase.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeBase.cs
index 29afd79895..3fa1ad6040 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeCollectionBase.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeCollectionBase.cs
index 3d8839313f..2712965d5a 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeCollectionBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/NodeCollectionBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.DatabaseModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/PrimaryIndex.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/PrimaryIndex.cs
index 75c205e02d..8ddf4b7929 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/PrimaryIndex.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/PrimaryIndex.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Ref.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Ref.cs
index 1eee59cc92..c244f3a7e0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Ref.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Ref.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Role.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Role.cs
index f004264e18..702ab08c82 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Role.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Role.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.DatabaseModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleCollection.cs
index 0eecf9fa92..c593f354b0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRef.cs
index 427f86f72a..1a1e32c635 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRef.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRefCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRefCollection.cs
index adda544c0f..2c54c19096 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRefCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/RoleRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Schema.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Schema.cs
index 5a8dd1c827..d5c93e98aa 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Schema.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Schema.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SchemaCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SchemaCollection.cs
index 651a456b21..ac93655250 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SchemaCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SchemaCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SecondaryIndex.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SecondaryIndex.cs
index 51439de0cc..8f9de43e67 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SecondaryIndex.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/SecondaryIndex.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Security.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Security.cs
index 77199376c9..12c7d80060 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Security.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Security.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Server.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Server.cs
index 0bafffe518..8c00ddf1fb 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Server.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Server.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Actions;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Table.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Table.cs
index 8e7b59e6ea..0a9fb75f2e 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Table.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/Table.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/TableCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/TableCollection.cs
index 7c5b0182b1..c48c0d6d59 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/TableCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/TableCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/User.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/User.cs
index 53f13312c2..c636052ea7 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/User.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/User.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/UserCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/UserCollection.cs
index 2683106acc..3d2e3f663d 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/UserCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModel/UserCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.DatabaseModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModelTest.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModelTest.cs
index a41d8497a2..6dbc2a5104 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModelTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/DatabaseModelTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfo.cs
index d47c3b9dae..f02b956162 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoCollection.cs
index 7011fd26aa..bdaae5ceb7 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoRef.cs
index 7fe17fe2d3..c061cb3eee 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ColumnInfoRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Exceptions/ValidationException.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Exceptions/ValidationException.cs
index a6647d965d..b09ba07dfb 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Exceptions/ValidationException.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Exceptions/ValidationException.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyCollection.cs
index 9c02cab018..b3af6366f0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnCollection.cs
index 6b91936604..a2fc1149ec 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnRef.cs
index 7f469190d0..ff1a454cf7 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyInfo.cs
index c34be4bd48..7880bbc065 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ForeignKeyInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRef.cs
index c30dca295b..2599b60bfa 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRef.cs
@@ -5,7 +5,6 @@
 // Created:    2010.01.14
 
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRefCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRefCollection.cs
index bec3e5c118..b2411baba1 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.14
 
-using System;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextIndexInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextIndexInfo.cs
index 2409eea7cf..ddd60963e4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextIndexInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/FullTextIndexInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.14
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRef.cs
index 75fbaffe6e..94e67e7cb4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRefCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRefCollection.cs
index 3f4e5288c7..803858f30e 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IncludedColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IndexInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IndexInfo.cs
index 6224231d9c..f535b63377 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IndexInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/IndexInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef.cs
index 8d1bb3b135..0bbf5c8aad 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRefCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRefCollection.cs
index 504a90d3d7..dbd7aa71e6 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef{TParent}.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef{TParent}.cs
index deb0282563..28dd12279f 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef{TParent}.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/KeyColumnRef{TParent}.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeBase.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeBase.cs
index c47f869a4d..d648cb4f66 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeBase.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeCollectionBase.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeCollectionBase.cs
index bbb648a25a..12153c3db6 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeCollectionBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/NodeCollectionBase.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryIndexInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryIndexInfo.cs
index 4c0811efa9..5c7a650ce6 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryIndexInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryIndexInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRef.cs
index 191a50fbe2..002d619c13 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRefCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRefCollection.cs
index 844273704e..8227543a60 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/PrimaryKeyColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Ref.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Ref.cs
index cd8e86d985..ae595bbccc 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Ref.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Ref.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ReferentialAction.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ReferentialAction.cs
index 36a0342367..5555ceac70 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ReferentialAction.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ReferentialAction.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.17
 
-using System;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Resources/Strings.Designer.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Resources/Strings.Designer.cs
index a3a100a1c4..431d80644c 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Resources/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/Resources/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Modelling.IndexingModel.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfo.cs
index 41cf92906f..1017a12f5f 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfoCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfoCollection.cs
index 1975d2e956..dd5f51699d 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfoCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/SecondaryIndexInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/StorageInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/StorageInfo.cs
index 8f59c25582..5113d4b029 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/StorageInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/StorageInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Actions;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfo.cs
index 296d2a8178..4197ed5fa7 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfo.cs
@@ -4,10 +4,8 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfoCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfoCollection.cs
index a0a66c6bd1..2781937004 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfoCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TableInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TypeInfo.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TypeInfo.cs
index 4354074352..6594309513 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TypeInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/TypeInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using System.Globalization;
 using Xtensive.Core;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRef.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRef.cs
index 68b09354e7..2457eff5b4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRef.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRefCollection.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRefCollection.cs
index 59036d095d..cd11926ab4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModel/ValueColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 namespace Xtensive.Orm.Tests.Core.Modelling.IndexingModel
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModelTest.cs b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModelTest.cs
index c17e16a1f2..79e5b6d3e4 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModelTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Modelling/IndexingModelTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.17
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
@@ -13,7 +11,6 @@
 using Xtensive.Modelling.Actions;
 using Xtensive.Modelling.Comparison;
 using Xtensive.Modelling.Comparison.Hints;
-using System.Linq;
 using Xtensive.Orm.Tests.Core.Modelling.IndexingModel;
 
 namespace Xtensive.Orm.Tests.Core.Modelling
diff --git a/Orm/Xtensive.Orm.Tests.Core/Parameters/ParametersTest.cs b/Orm/Xtensive.Orm.Tests.Core/Parameters/ParametersTest.cs
index c4a2fca1ee..ec00fcde17 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Parameters/ParametersTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Parameters/ParametersTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.08.18
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Performance/ComparerPerformanceTest.cs b/Orm/Xtensive.Orm.Tests.Core/Performance/ComparerPerformanceTest.cs
index fef2d0af04..a8fa0e1685 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Performance/ComparerPerformanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Performance/ComparerPerformanceTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.23
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
 using NUnit.Framework;
 using Xtensive.Comparison;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Performance/TuplePerformanceTest.cs b/Orm/Xtensive.Orm.Tests.Core/Performance/TuplePerformanceTest.cs
index 8b0d134824..0a05dd6827 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Performance/TuplePerformanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Performance/TuplePerformanceTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.11.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Reflection/AttributeHelperTest.cs b/Orm/Xtensive.Orm.Tests.Core/Reflection/AttributeHelperTest.cs
index 54fb8c34bf..c657adb658 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Reflection/AttributeHelperTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Reflection/AttributeHelperTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Reflection/DelegateHelperCreateDelegateTest.cs b/Orm/Xtensive.Orm.Tests.Core/Reflection/DelegateHelperCreateDelegateTest.cs
index 596505b3e4..57dff7c480 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Reflection/DelegateHelperCreateDelegateTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Reflection/DelegateHelperCreateDelegateTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.09
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericInterfaceTests.cs b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericInterfaceTests.cs
index f33bd89487..d01fee0e4c 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericInterfaceTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericInterfaceTests.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericTypeTests.cs b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericTypeTests.cs
index c5302badf9..0e363a68b7 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericTypeTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericTypeTests.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTest.cs b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTest.cs
index 9ff64c2574..4c0455a1fd 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.17
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Reflection;
 using NUnit.Framework;
@@ -14,7 +12,6 @@
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Orm.Tests;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Core.Reflection
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTestModel.cs b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTestModel.cs
index f664dbab04..2331e6b637 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTestModel.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperTestModel.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.20
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests.Core.Reflection
 {
diff --git a/Orm/Xtensive.Orm.Tests.Core/Resources/TestResources.Designer.cs b/Orm/Xtensive.Orm.Tests.Core/Resources/TestResources.Designer.cs
index b282f33bf2..1dcadf0c74 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Resources/TestResources.Designer.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Resources/TestResources.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive.Resources {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm.Tests.Core/Testing/InstanceGeneratorTest.cs b/Orm/Xtensive.Orm.Tests.Core/Testing/InstanceGeneratorTest.cs
index 4b49d810cf..dca007e5ca 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Testing/InstanceGeneratorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Testing/InstanceGeneratorTest.cs
@@ -4,8 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.24
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Orm.Logging;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Testing/RandomManagerTest.cs b/Orm/Xtensive.Orm.Tests.Core/Testing/RandomManagerTest.cs
index 0365756889..7a2ccf6af8 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Testing/RandomManagerTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Testing/RandomManagerTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.09
 
-using System;
 using System.Runtime.CompilerServices;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/DateTimeOffsetTupleTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/DateTimeOffsetTupleTest.cs
index dea263423b..2878e71d47 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/DateTimeOffsetTupleTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/DateTimeOffsetTupleTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Text;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/DifferentialTupleTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/DifferentialTupleTest.cs
index a3321301e8..3536da4a86 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/DifferentialTupleTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/DifferentialTupleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2008.05.23
 
-using System.Collections.Generic;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/DummyTuple.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/DummyTuple.cs
index 6a0997aa81..3e0eedc93a 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/DummyTuple.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/DummyTuple.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.24
 
-using System;
 using System.Collections;
 using Xtensive.Core;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/LongTupleTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/LongTupleTest.cs
index 91dac38372..615284f56c 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/LongTupleTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/LongTupleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2011.04.18
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/CutInTransformTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/CutInTransformTest.cs
index 47c4971b95..1985e02a50 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/CutInTransformTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/CutInTransformTest.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.06.23
 
-using System;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/MergeTransformTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/MergeTransformTest.cs
index 96e33fc3ab..51380a6b16 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/MergeTransformTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/MergeTransformTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.05
 
-using System;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/ReadOnlyTransformTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/ReadOnlyTransformTest.cs
index 83be58a70b..1abdd62eb0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/ReadOnlyTransformTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/ReadOnlyTransformTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.05
 
-using System;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/SegmentTransformTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/SegmentTransformTest.cs
index 3ff89f7945..aa438dc55a 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/SegmentTransformTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/Transform/SegmentTransformTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.05
 
-using System;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTest.cs
index c42417c4ec..79543a15fd 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.24
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTestBase.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTestBase.cs
index 1ef1abb0c1..1beb058d45 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleBehaviorTestBase.cs
@@ -4,9 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2008.05.23
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleComparerTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleComparerTest.cs
index 57d642c12a..62192b9ed0 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleComparerTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleComparerTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2007.08.23
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleDescriptorTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleDescriptorTest.cs
index c228d2dba9..83d83ba5f3 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleDescriptorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleDescriptorTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.25
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Tuples;
 
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/TuplePerformanceTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/TuplePerformanceTest.cs
index 719f6eac76..c15a8ce33f 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/TuplePerformanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/TuplePerformanceTest.cs
@@ -1,7 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleSerializationTest.cs b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleSerializationTest.cs
index 324dc06dfb..c89f0f3387 100644
--- a/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleSerializationTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Core/Tuples/TupleSerializationTest.cs
@@ -8,6 +8,7 @@
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
 using Xtensive.Tuples;
+using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm.Tests.Core.Tuples
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/AssertEx.cs b/Orm/Xtensive.Orm.Tests.Framework/AssertEx.cs
index 8b376ccbec..fa453a8b81 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/AssertEx.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/AssertEx.cs
@@ -4,9 +4,6 @@
 // Created by: 
 // Created:    2007.10.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text.RegularExpressions;
 using JetBrains.Annotations;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/AutoBuildTest.cs b/Orm/Xtensive.Orm.Tests.Framework/AutoBuildTest.cs
index e44a985444..7faf14aab9 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/AutoBuildTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/AutoBuildTest.cs
@@ -6,7 +6,6 @@
 
 using System.Diagnostics;
 using NUnit.Framework;
-using System;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/DebugInfo.cs b/Orm/Xtensive.Orm.Tests.Framework/DebugInfo.cs
index 9403b681e0..81cfaefa9c 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/DebugInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/DebugInfo.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Security;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/DomainModelExtensions.cs b/Orm/Xtensive.Orm.Tests.Framework/DomainModelExtensions.cs
index 56c703f4e1..cdb2f5d2f5 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/DomainModelExtensions.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/DomainModelExtensions.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.06.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Dynamic.cs b/Orm/Xtensive.Orm.Tests.Framework/Dynamic.cs
index 01ce6463cf..da65c1988b 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Dynamic.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Dynamic.cs
@@ -1,12 +1,10 @@
 //Copyright (C) Microsoft Corporation.  All rights reserved.
 
-using System.Collections.Generic;
 using System.Globalization;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Reflection.Emit;
 using System.Text;
-using System.Threading;
 
 namespace System.Linq.Dynamic
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/HighResolutionTime.cs b/Orm/Xtensive.Orm.Tests.Framework/HighResolutionTime.cs
index 74aca1db73..260030e726 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/HighResolutionTime.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/HighResolutionTime.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.06.11
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/IndexInfoExtensions.cs b/Orm/Xtensive.Orm.Tests.Framework/IndexInfoExtensions.cs
index 3012b11b87..dc2a5cdbab 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/IndexInfoExtensions.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/IndexInfoExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.09
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/InheritanceSchemaModifier.cs b/Orm/Xtensive.Orm.Tests.Framework/InheritanceSchemaModifier.cs
index 27af780dc0..35bc092994 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/InheritanceSchemaModifier.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/InheritanceSchemaModifier.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.05
 
-using System;
 using Xtensive.Orm;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/InstanceGenerationUtils.cs b/Orm/Xtensive.Orm.Tests.Framework/InstanceGenerationUtils.cs
index 630a5fa223..41ad5195ab 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/InstanceGenerationUtils.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/InstanceGenerationUtils.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.12
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/InstanceGeneratorProvider.cs b/Orm/Xtensive.Orm.Tests.Framework/InstanceGeneratorProvider.cs
index 89fea6a73d..806e114d92 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/InstanceGeneratorProvider.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/InstanceGeneratorProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.17
 
-using System;
 using System.Collections.Concurrent;
 using System.Diagnostics;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGenerator.cs
index 7efff9b4ea..b592cab5fc 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGenerator.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.16
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorBase.cs b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorBase.cs
index 756e92199e..4633601d85 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.03.07
 
-using System;
 using System.Collections;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorProvider.cs b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorProvider.cs
index 5e10b3babc..7b4b064bc5 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorProvider.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IInstanceGeneratorProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IStorageTimeZoneProvider.cs b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IStorageTimeZoneProvider.cs
index c8ab060896..9e184bb0c3 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IStorageTimeZoneProvider.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Interfaces/IStorageTimeZoneProvider.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/ArrayInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/ArrayInstanceGenerator.cs
index 44cc5d9604..ab98212259 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/ArrayInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/ArrayInstanceGenerator.cs
@@ -5,8 +5,6 @@
 // Created:    2008.01.25
 
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/BooleanInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/BooleanInstanceGenerator.cs
index 744082c6b8..e14e1e9b25 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/BooleanInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/BooleanInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/ByteInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/ByteInstanceGenerator.cs
index 211add9df5..0fb4dfa1dd 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/ByteInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/ByteInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/CharInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/CharInstanceGenerator.cs
index 07df3e2936..3b4f10b985 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/CharInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/CharInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeInstanceGenerator.cs
index bafd787548..9727b73964 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.22
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeOffsetInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeOffsetInstanceGenerator.cs
index e71e815929..99072d6008 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeOffsetInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/DateTimeOffsetInstanceGenerator.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/DecimalInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/DecimalInstanceGenerator.cs
index 2111598314..a7de529031 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/DecimalInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/DecimalInstanceGenerator.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.24
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/DoubleInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/DoubleInstanceGenerator.cs
index 25af52d410..3d8d934d0d 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/DoubleInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/DoubleInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/EnumInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/EnumInstanceGenerator.cs
index d401809c28..8a139f9b66 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/EnumInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/EnumInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.23
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/GuidInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/GuidInstanceGenerator.cs
index 7d0d3743bb..a9d17068be 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/GuidInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/GuidInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.22
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/InstanceGeneratorBase.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/InstanceGeneratorBase.cs
index d51ce30d34..1a737214f7 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/InstanceGeneratorBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/InstanceGeneratorBase.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/Int16InstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/Int16InstanceGenerator.cs
index c2b638adf5..b7d3cf793e 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/Int16InstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/Int16InstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/Int32InstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/Int32InstanceGenerator.cs
index 8c79942cb3..277a8b8769 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/Int32InstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/Int32InstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/Int64InstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/Int64InstanceGenerator.cs
index 5810ab70f8..f43298eb85 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/Int64InstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/Int64InstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/KeyValuePairInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/KeyValuePairInstanceGenerator.cs
index f8e5d0be4e..980e11c049 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/KeyValuePairInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/KeyValuePairInstanceGenerator.cs
@@ -5,8 +5,6 @@
 // Created:    2008.01.25
 
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/NullableInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/NullableInstanceGenerator.cs
index f895aa9fef..669e16363a 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/NullableInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/NullableInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.23
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/PairInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/PairInstanceGenerator.cs
index 7727f29a86..45fb6ca662 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/PairInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/PairInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.25
 
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/SByteInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/SByteInstanceGenerator.cs
index 0d6f8c6862..68cdd2b7a0 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/SByteInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/SByteInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/SingleInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/SingleInstanceGenerator.cs
index fdbaac7554..adb61c9d9d 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/SingleInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/SingleInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/StringInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/StringInstanceGenerator.cs
index 9800e7ca33..c28f774950 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/StringInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/StringInstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.22
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/TupleInstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/TupleInstanceGenerator.cs
index ff5ab8e455..2f29555c83 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/TupleInstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/TupleInstanceGenerator.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.30
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt16InstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt16InstanceGenerator.cs
index aa9573ebb1..644c32438b 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt16InstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt16InstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt32InstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt32InstanceGenerator.cs
index 82b895543f..77872576ab 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt32InstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt32InstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt64InstanceGenerator.cs b/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt64InstanceGenerator.cs
index e39c8fbdc7..1e0445a8d8 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt64InstanceGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Internals/UInt64InstanceGenerator.cs
@@ -5,7 +5,6 @@
 // Created:    2008.01.18
 
 
-using System;
 
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Measurement.cs b/Orm/Xtensive.Orm.Tests.Framework/Measurement.cs
index 8509b7df26..b5e84ac5ab 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Measurement.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Measurement.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.06.11
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/MeasurementOptions.cs b/Orm/Xtensive.Orm.Tests.Framework/MeasurementOptions.cs
index 5727bd0283..48417137f5 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/MeasurementOptions.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/MeasurementOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/ModelBuildingTest.cs b/Orm/Xtensive.Orm.Tests.Framework/ModelBuildingTest.cs
index 2980757ad5..a189a01072 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/ModelBuildingTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/ModelBuildingTest.cs
@@ -4,11 +4,8 @@
 // Created by: Alexey Kulakov
 // Created:    2018.10.01
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/RandomManager.cs b/Orm/Xtensive.Orm.Tests.Framework/RandomManager.cs
index 012c84a6f0..145d34c185 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/RandomManager.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/RandomManager.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.09
 
-using System;
 using System.Diagnostics;
 using System.IO;
 using System.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/Require.cs b/Orm/Xtensive.Orm.Tests.Framework/Require.cs
index 6d5ccf2f34..e1f3cfe084 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/Require.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/Require.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/RuntimeInfo.cs b/Orm/Xtensive.Orm.Tests.Framework/RuntimeInfo.cs
index 8af57d2405..2797c9a6ad 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/RuntimeInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/RuntimeInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.04.17
 
-using System;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/SeedVariatorType.cs b/Orm/Xtensive.Orm.Tests.Framework/SeedVariatorType.cs
index cc679d9927..de56e431d6 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/SeedVariatorType.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/SeedVariatorType.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.09
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/StorageProvider.cs b/Orm/Xtensive.Orm.Tests.Framework/StorageProvider.cs
index d1e3228b11..be3fb12a9f 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/StorageProvider.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/StorageProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.09
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/StorageProviderInfo.cs b/Orm/Xtensive.Orm.Tests.Framework/StorageProviderInfo.cs
index 13d3a40222..ae5fb271b6 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/StorageProviderInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/StorageProviderInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.07.23
 
-using System;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/StorageProviderVersion.cs b/Orm/Xtensive.Orm.Tests.Framework/StorageProviderVersion.cs
index c45858ca46..111e49de78 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/StorageProviderVersion.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/StorageProviderVersion.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.11
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/StorageTestHelper.cs b/Orm/Xtensive.Orm.Tests.Framework/StorageTestHelper.cs
index 3b9a86d479..df80bf105b 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/StorageTestHelper.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/StorageTestHelper.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.17
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/StorageTimeZoneProvider.cs b/Orm/Xtensive.Orm.Tests.Framework/StorageTimeZoneProvider.cs
index c5c587c42d..daa696343e 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/StorageTimeZoneProvider.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/StorageTimeZoneProvider.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/TestConfiguration.cs b/Orm/Xtensive.Orm.Tests.Framework/TestConfiguration.cs
index 835f0088d5..c708245f74 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/TestConfiguration.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/TestConfiguration.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.11
 
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/TestHelper.cs b/Orm/Xtensive.Orm.Tests.Framework/TestHelper.cs
index e53e5398c8..7ab95db26d 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/TestHelper.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/TestHelper.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.09
 
-using System;
-using System.Collections.Generic;
-using System.Threading;
 using Xtensive.Sql.Dml;
 
 
diff --git a/Orm/Xtensive.Orm.Tests.Framework/TestInfo.cs b/Orm/Xtensive.Orm.Tests.Framework/TestInfo.cs
index 799b54c27d..faea399ef5 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/TestInfo.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/TestInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.09
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/TestSqlDriver.cs b/Orm/Xtensive.Orm.Tests.Framework/TestSqlDriver.cs
index ad793b3d96..bdfdd889a7 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/TestSqlDriver.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/TestSqlDriver.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/TypeIdModifier.cs b/Orm/Xtensive.Orm.Tests.Framework/TypeIdModifier.cs
index 22e5b06fb9..e823799138 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/TypeIdModifier.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/TypeIdModifier.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.05
 
-using System;
 using Xtensive.Orm;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests.Framework/WellKnownDatabases.cs b/Orm/Xtensive.Orm.Tests.Framework/WellKnownDatabases.cs
index b08ff63036..ab083832fa 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/WellKnownDatabases.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/WellKnownDatabases.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/WellKnownSchemas.cs b/Orm/Xtensive.Orm.Tests.Framework/WellKnownSchemas.cs
index b9468cd599..ce7b708810 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/WellKnownSchemas.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/WellKnownSchemas.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 
 namespace Xtensive.Orm.Tests
diff --git a/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2, TBase3}.cs b/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2, TBase3}.cs
index 40747900a8..6e480362fd 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2, TBase3}.cs	
+++ b/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2, TBase3}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.21
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2}.cs b/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2}.cs
index 2c9fdd6537..31b043a967 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2}.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase1,TBase2}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.21
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase}.cs b/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase}.cs
index 40529e185d..4ecc82589c 100644
--- a/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase}.cs
+++ b/Orm/Xtensive.Orm.Tests.Framework/WrappingInstanceGenerator{T,TBase}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.21
 
-using System;
 
 namespace Xtensive.Orm.Tests
 {
diff --git a/Orm/Xtensive.Orm.Tests.Sql/ChinookSchemaCreator.cs b/Orm/Xtensive.Orm.Tests.Sql/ChinookSchemaCreator.cs
index 0d0c3897f6..6d8884211d 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/ChinookSchemaCreator.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/ChinookSchemaCreator.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2019.10.03
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Xml.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/ChinookTestBase.cs b/Orm/Xtensive.Orm.Tests.Sql/ChinookTestBase.cs
index 1a1435ad23..a9a01effac 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/ChinookTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/ChinookTestBase.cs
@@ -4,10 +4,8 @@
 // Created by: Malisa Ncube
 // Created:    2011.03.17
 
-using System;
 using System.Data;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/CloneTests.cs b/Orm/Xtensive.Orm.Tests.Sql/CloneTests.cs
index 6de9f4081d..0b699656d5 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/CloneTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/CloneTests.cs
@@ -3,9 +3,6 @@
 // See the License.txt file in the project root for more information.
 
 using NUnit.Framework;
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/CompilerTest.cs b/Orm/Xtensive.Orm.Tests.Sql/CompilerTest.cs
index 63ac0302a6..093cb2dda4 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/CompilerTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/CompilerTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Ddl;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/DateTimeIntervalTest.cs b/Orm/Xtensive.Orm.Tests.Sql/DateTimeIntervalTest.cs
index d82c295977..039b9a039e 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/DateTimeIntervalTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/DateTimeIntervalTest.cs
@@ -5,7 +5,6 @@
 // Created:    2009.02.27
 
 using NUnit.Framework;
-using System;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm.Tests.Sql/DateTimeOffsetTest.cs b/Orm/Xtensive.Orm.Tests.Sql/DateTimeOffsetTest.cs
index 608765bfa2..168088b1e8 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/DateTimeOffsetTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/DateTimeOffsetTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.01.16
 
-using System;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/DriverFactoryTest.cs b/Orm/Xtensive.Orm.Tests.Sql/DriverFactoryTest.cs
index fc7d5fa952..a7a4d7b768 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/DriverFactoryTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/DriverFactoryTest.cs
@@ -2,15 +2,12 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Sql;
 using Xtensive.Orm.Tests.Sql.DriverFactoryTestTypes;
-using System.Threading.Tasks;
-using System.Threading;
 
 namespace Xtensive.Orm.Tests.Sql.DriverFactoryTestTypes
 {
diff --git a/Orm/Xtensive.Orm.Tests.Sql/ExceptionTypesTest.cs b/Orm/Xtensive.Orm.Tests.Sql/ExceptionTypesTest.cs
index c5e4bc1001..4b59f9b355 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/ExceptionTypesTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/ExceptionTypesTest.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Data;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/ExtractorTestBase.cs b/Orm/Xtensive.Orm.Tests.Sql/ExtractorTestBase.cs
index 41e6db2349..adc108e3ea 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/ExtractorTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/ExtractorTestBase.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Microsoft.VisualBasic;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Firebird/ChinookTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Firebird/ChinookTest.cs
index 99c1998825..b7aac3c6ec 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Firebird/ChinookTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Firebird/ChinookTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Firebird/ExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Firebird/ExtractorTest.cs
index 96f6971d06..ecc2609b0b 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Firebird/ExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Firebird/ExtractorTest.cs
@@ -5,7 +5,6 @@
 // Created:    2011.01.13
 
 using NUnit.Framework;
-using System;
 using System.Text;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Firebird/QueryTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Firebird/QueryTest.cs
index c3e19b4997..52025febeb 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Firebird/QueryTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Firebird/QueryTest.cs
@@ -1,4 +1,3 @@
-using System;
 using NUnit.Framework;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Firebird/SavepointTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Firebird/SavepointTest.cs
index d8ffd93553..89fb62f465 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Firebird/SavepointTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Firebird/SavepointTest.cs
@@ -5,7 +5,6 @@
 // Created:    2011.01.21
 
 using NUnit.Framework;
-using System;
 
 namespace Xtensive.Orm.Tests.Sql.Firebird
 {
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Firebird/TestHelpers.cs b/Orm/Xtensive.Orm.Tests.Sql/Firebird/TestHelpers.cs
index 8cf1ea0d9a..d019245073 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Firebird/TestHelpers.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Firebird/TestHelpers.cs
@@ -6,8 +6,6 @@
 
 using System.Data.Common;
 using System.Diagnostics;
-using System.Collections.Generic;
-using System;
 
 namespace Xtensive.Orm.Tests.Sql.Firebird
 {
diff --git a/Orm/Xtensive.Orm.Tests.Sql/IndexTest.cs b/Orm/Xtensive.Orm.Tests.Sql/IndexTest.cs
index 77b6d6614c..8d047e19a5 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/IndexTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/IndexTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.31
 
-using System;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MakeNamesUnreadableTest.cs b/Orm/Xtensive.Orm.Tests.Sql/MakeNamesUnreadableTest.cs
index 8d58a76425..c53622cb53 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MakeNamesUnreadableTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MakeNamesUnreadableTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.24
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MySQL/ChinookTest.cs b/Orm/Xtensive.Orm.Tests.Sql/MySQL/ChinookTest.cs
index 41ee3c306b..736c63e2a3 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MySQL/ChinookTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MySQL/ChinookTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MySQL/DateTimeIntervalTests.cs b/Orm/Xtensive.Orm.Tests.Sql/MySQL/DateTimeIntervalTests.cs
index bb41093cb2..4111d849e8 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MySQL/DateTimeIntervalTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MySQL/DateTimeIntervalTests.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.03.22
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MySQL/MiscTests.cs b/Orm/Xtensive.Orm.Tests.Sql/MySQL/MiscTests.cs
index aac4cc7700..da9aa20ad6 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MySQL/MiscTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MySQL/MiscTests.cs
@@ -4,13 +4,10 @@
 // Created by: Malisa Ncube
 // Created:    2011.03.17
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
 using System.Diagnostics;
 using System.IO;
-using System.Linq;
 using System.Runtime.Serialization.Formatters.Binary;
 using System.Text;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MySQL/Sakila.cs b/Orm/Xtensive.Orm.Tests.Sql/MySQL/Sakila.cs
index 29da0c9d35..dabf781bc4 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MySQL/Sakila.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MySQL/Sakila.cs
@@ -4,11 +4,8 @@
 // Created by: Malisa Ncube
 // Created:    2011.03.17
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.IO;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MySQL/SakilaExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/MySQL/SakilaExtractorTest.cs
index 1edcd2ff6f..6a460ea33a 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MySQL/SakilaExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MySQL/SakilaExtractorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.02.25
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/MySQL/TypeMappingTests.cs b/Orm/Xtensive.Orm.Tests.Sql/MySQL/TypeMappingTests.cs
index 41792b23ae..edeccbe844 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/MySQL/TypeMappingTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/MySQL/TypeMappingTests.cs
@@ -4,9 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.03.23
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Oracle/ChinookTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Oracle/ChinookTest.cs
index a9a62214c5..4e7da2e4d6 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Oracle/ChinookTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Oracle/ChinookTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Oracle/ExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Oracle/ExtractorTest.cs
index 72dc96c2eb..69d61945d2 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Oracle/ExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Oracle/ExtractorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.29
 
-using System;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Oracle/UberTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Oracle/UberTest.cs
index 23e9bd575b..be05a8d244 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Oracle/UberTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Oracle/UberTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/CatalogComparer.cs b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/CatalogComparer.cs
index 279200e8fe..9307ea1c78 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/CatalogComparer.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/CatalogComparer.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/ChinookTest.cs b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/ChinookTest.cs
index fb0ef3e327..7362832474 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/ChinookTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/ChinookTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/IndexTest.cs b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/IndexTest.cs
index 9aad5574b2..4d282b8d7d 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/IndexTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/IndexTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.31
 
-using System;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/NpgsqlTypeConstructorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/NpgsqlTypeConstructorTest.cs
index 36037d4c60..aab46a7cae 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/NpgsqlTypeConstructorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/NpgsqlTypeConstructorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.14
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Providers.PostgreSql;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/SqlDomTests.cs b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/SqlDomTests.cs
index 10e5154b17..69826fecb6 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/SqlDomTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/PostgreSql/SqlDomTests.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data;
 using System.Data.Common;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/ReplaceTests.cs b/Orm/Xtensive.Orm.Tests.Sql/ReplaceTests.cs
index bad15106fe..f7b9f41177 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/ReplaceTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/ReplaceTests.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SavepointsTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SavepointsTest.cs
index c9b4b33b55..456fd58c2d 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SavepointsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SavepointsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.20
 
-using System;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlDateTimePartsTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlDateTimePartsTest.cs
index 9adc0a8b91..049cc2c90d 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlDateTimePartsTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlDateTimePartsTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlHelperQuotationTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlHelperQuotationTest.cs
index 5e466ec3ac..27bab6faad 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlHelperQuotationTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlHelperQuotationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.04.23
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlInsertTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlInsertTest.cs
index 97be5f6739..5c803a87ef 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlInsertTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlInsertTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/AdventureWorks.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/AdventureWorks.cs
index a6558fe1c4..169f7d81e7 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/AdventureWorks.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/AdventureWorks.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Data;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/CompilerTests.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/CompilerTests.cs
index 006fe88e33..2b7aa2e4dd 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/CompilerTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/CompilerTests.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System.Collections.Generic;
 using NUnit.Framework;
-using System;
 using System.Data;
 using System.Data.Common;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ConnectionTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ConnectionTest.cs
index 5015b63512..d1045555df 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ConnectionTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ConnectionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.10.30
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ErrorMessageParserTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ErrorMessageParserTest.cs
index 7ed3a0297e..a566975552 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ErrorMessageParserTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ErrorMessageParserTest.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.28
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Sql.Drivers.SqlServer;
 
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ExtractorTest.cs
index 2d6f4b6b39..fa87997b72 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/ExtractorTest.cs
@@ -6,10 +6,7 @@
 
 // TODO: Refactor stupid MSSqlExtractorTests.cs and put all stuff here
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/IndexTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/IndexTest.cs
index 072f2fe9f7..3f4881adaf 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/IndexTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/IndexTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.31
 
-using System;
 using NUnit.Framework;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLExtractorTests.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLExtractorTests.cs
index b59d442e33..4b3a866a99 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLExtractorTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLExtractorTests.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLTests.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLTests.cs
index 6952bdda8f..bec8937936 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MSSQLTests.cs
@@ -4,7 +4,6 @@
 
 using System.Diagnostics;
 using NUnit.Framework;
-using System;
 using System.Data;
 using System.Data.Common;
 using Xtensive.Sql;
@@ -13,9 +12,7 @@
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
 using Index = Xtensive.Sql.Model.Index;
-using System.Linq;
 using Xtensive.Core;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests.Sql.SqlServer
 {
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MiscTests.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MiscTests.cs
index 9b8faa6606..86069f8899 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MiscTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/MiscTests.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data;
 using System.IO;
 using System.Runtime.Serialization.Formatters.Binary;
@@ -12,7 +11,6 @@
 using Xtensive.Sql.Compiler;
 using Xtensive.Sql.Dml;
 using System.Data.Common;
-using System.Linq;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Orm.Tests.Sql.SqlServer
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/SqlDecimalTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/SqlDecimalTest.cs
index 478f71d452..eb5c6c3949 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServer/SqlDecimalTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServer/SqlDecimalTest.cs
@@ -4,13 +4,10 @@
 // Created by: Denis Kudelin
 // Created:    2019.03.19
 
-using System;
-using System.Collections.Generic;
 using Microsoft.Data.SqlClient;
 using System.Data.SqlTypes;
 using System.Diagnostics;
 using System.Globalization;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlServerCe/ExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlServerCe/ExtractorTest.cs
index 88c2b4f828..b6a2579e80 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlServerCe/ExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlServerCe/ExtractorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.29
 
-using System;
 using NUnit.Framework;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests.Sql/SqlTest.cs b/Orm/Xtensive.Orm.Tests.Sql/SqlTest.cs
index dc1abfc383..737fedc24a 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/SqlTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/SqlTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.21
 
-using System;
 using System.Data;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ChinookTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ChinookTest.cs
index c61ebd20da..ccb19019e8 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ChinookTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ChinookTest.cs
@@ -4,11 +4,9 @@
 // Created by: Malisa Ncube
 // Created:    2011.06.10
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ExtractorTest.cs b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ExtractorTest.cs
index 1e294c8bff..2e16021db3 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/ExtractorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.03.16
 
-using System;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/MiscTests.cs b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/MiscTests.cs
index 8e083188e7..557a559520 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/MiscTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/MiscTests.cs
@@ -4,7 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.05.13
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/TypeMappingTests.cs b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/TypeMappingTests.cs
index 2a405d2db8..7b5119c5db 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/Sqlite/TypeMappingTests.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/Sqlite/TypeMappingTests.cs
@@ -4,9 +4,6 @@
 // Created by: Malisa Ncube
 // Created:    2011.05.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Sql;
diff --git a/Orm/Xtensive.Orm.Tests.Sql/TypeMappingTest.cs b/Orm/Xtensive.Orm.Tests.Sql/TypeMappingTest.cs
index da8044d593..54d8333236 100644
--- a/Orm/Xtensive.Orm.Tests.Sql/TypeMappingTest.cs
+++ b/Orm/Xtensive.Orm.Tests.Sql/TypeMappingTest.cs
@@ -5,11 +5,8 @@
 // Created:    2009.07.08
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Linq;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm.Tests/Configuration/AppConfigTest.cs b/Orm/Xtensive.Orm.Tests/Configuration/AppConfigTest.cs
index 431ec53969..59d3fd6392 100644
--- a/Orm/Xtensive.Orm.Tests/Configuration/AppConfigTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Configuration/AppConfigTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2008.08.06
 
-using System;
 using System.Configuration;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Linq;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Configuration/MaxNumberOfConditionsTest.cs b/Orm/Xtensive.Orm.Tests/Configuration/MaxNumberOfConditionsTest.cs
index dfa095b2fa..0d739691a2 100644
--- a/Orm/Xtensive.Orm.Tests/Configuration/MaxNumberOfConditionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Configuration/MaxNumberOfConditionsTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Configuration
diff --git a/Orm/Xtensive.Orm.Tests/Configuration/SchemaTest.cs b/Orm/Xtensive.Orm.Tests/Configuration/SchemaTest.cs
index e102a6a01d..4442c8716b 100644
--- a/Orm/Xtensive.Orm.Tests/Configuration/SchemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Configuration/SchemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2013.10.04
 
-using System;
 using System.Diagnostics;
 using System.IO;
 using System.Xml;
diff --git a/Orm/Xtensive.Orm.Tests/Configuration/SessionInitializationTest.cs b/Orm/Xtensive.Orm.Tests/Configuration/SessionInitializationTest.cs
index 1286c9695a..2bfc047182 100644
--- a/Orm/Xtensive.Orm.Tests/Configuration/SessionInitializationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Configuration/SessionInitializationTest.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.13
 
-using System;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Configuration/TypeRegistryTest.cs b/Orm/Xtensive.Orm.Tests/Configuration/TypeRegistryTest.cs
index ec23029155..66f668ec80 100644
--- a/Orm/Xtensive.Orm.Tests/Configuration/TypeRegistryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Configuration/TypeRegistryTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.08
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/DomainConfigurationFactoryTest.cs b/Orm/Xtensive.Orm.Tests/DomainConfigurationFactoryTest.cs
index 8a27739fd2..839495b038 100644
--- a/Orm/Xtensive.Orm.Tests/DomainConfigurationFactoryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/DomainConfigurationFactoryTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.19
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Indexing/ForeignKeyInfoTest.cs b/Orm/Xtensive.Orm.Tests/Indexing/ForeignKeyInfoTest.cs
index 89b023b30e..fff2e6d7b8 100644
--- a/Orm/Xtensive.Orm.Tests/Indexing/ForeignKeyInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Indexing/ForeignKeyInfoTest.cs
@@ -9,6 +9,7 @@
 using Xtensive.Orm.Upgrade.Model;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
+using AggregateException = Xtensive.Core.AggregateException;
 
 namespace Xtensive.Orm.Tests.Indexing
 {
diff --git a/Orm/Xtensive.Orm.Tests/Indexing/PrimaryIndexInfoTest.cs b/Orm/Xtensive.Orm.Tests/Indexing/PrimaryIndexInfoTest.cs
index 7e1901b962..f832f3da2d 100644
--- a/Orm/Xtensive.Orm.Tests/Indexing/PrimaryIndexInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Indexing/PrimaryIndexInfoTest.cs
@@ -4,9 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.17
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Indexing/SecondaryIndexInfoTest.cs b/Orm/Xtensive.Orm.Tests/Indexing/SecondaryIndexInfoTest.cs
index adf2089c20..856cffe020 100644
--- a/Orm/Xtensive.Orm.Tests/Indexing/SecondaryIndexInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Indexing/SecondaryIndexInfoTest.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Indexing/StorageActionTest.cs b/Orm/Xtensive.Orm.Tests/Indexing/StorageActionTest.cs
index ac5e57b837..25069081e0 100644
--- a/Orm/Xtensive.Orm.Tests/Indexing/StorageActionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Indexing/StorageActionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Indexing/StorageInfoTest.cs b/Orm/Xtensive.Orm.Tests/Indexing/StorageInfoTest.cs
index 40c59b0805..509d8bfc18 100644
--- a/Orm/Xtensive.Orm.Tests/Indexing/StorageInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Indexing/StorageInfoTest.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.17
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceImplementationTest.cs b/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceImplementationTest.cs
index eea44d7db1..bc57a31ea4 100644
--- a/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceImplementationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceImplementationTest.cs
@@ -4,11 +4,9 @@
 // Created by: Alexis Kochetov
 // Created:    2010.05.18
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Interfaces.Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Interfaces
 {
diff --git a/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceTest.cs b/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceTest.cs
index c72e00aa5c..d8f931fdf2 100644
--- a/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Interfaces/InterfaceTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.08
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Interfaces/KeyStructureConflictTest.cs b/Orm/Xtensive.Orm.Tests/Interfaces/KeyStructureConflictTest.cs
index 63a58e9f09..a213079028 100644
--- a/Orm/Xtensive.Orm.Tests/Interfaces/KeyStructureConflictTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Interfaces/KeyStructureConflictTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.10
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Interfaces.KeyStructureConflictTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Interfaces/TypeIdModeConflictTest.cs b/Orm/Xtensive.Orm.Tests/Interfaces/TypeIdModeConflictTest.cs
index 4e8d982e31..c5ed000b92 100644
--- a/Orm/Xtensive.Orm.Tests/Interfaces/TypeIdModeConflictTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Interfaces/TypeIdModeConflictTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.14
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Interfaces.TypeIdModeConflictTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Interfaces/UnusedTypeRemovalTest.cs b/Orm/Xtensive.Orm.Tests/Interfaces/UnusedTypeRemovalTest.cs
index f6546ecd68..4cc888bdec 100644
--- a/Orm/Xtensive.Orm.Tests/Interfaces/UnusedTypeRemovalTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Interfaces/UnusedTypeRemovalTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.14
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/BatchingCommandProcessorFrenzy.cs b/Orm/Xtensive.Orm.Tests/Issues/BatchingCommandProcessorFrenzy.cs
index ecfe940992..c51e8a8404 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/BatchingCommandProcessorFrenzy.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/BatchingCommandProcessorFrenzy.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.20
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.BatchingCommandProcessorFrenzyModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerException.cs b/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerException.cs
index c3f525ecc9..58a52ff721 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerException.cs
@@ -4,14 +4,12 @@
 // Created by: Alexis Kochetov
 // Created:    2011.05.29
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.ProjectCustomCompilerException.Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerFeatureTest.cs b/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerFeatureTest.cs
index f32deb4f49..6920a7d1fa 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerFeatureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/CustomCompilerFeatureTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.05.29
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/InterfaceEntitySetTest.cs b/Orm/Xtensive.Orm.Tests/Issues/InterfaceEntitySetTest.cs
index c000beaae2..8b49149b18 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/InterfaceEntitySetTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/InterfaceEntitySetTest.cs
@@ -1,4 +1,3 @@
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0001_MultipleHierarchyRootAttributes.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0001_MultipleHierarchyRootAttributes.cs
index eece89cd1c..bf49e49ef8 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0001_MultipleHierarchyRootAttributes.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0001_MultipleHierarchyRootAttributes.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.16
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0002_PrimaryKeyWithLazyLoad.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0002_PrimaryKeyWithLazyLoad.cs
index c1dae318c1..d4eaa04a98 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0002_PrimaryKeyWithLazyLoad.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0002_PrimaryKeyWithLazyLoad.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.16
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0003_NullablePrimaryKey.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0003_NullablePrimaryKey.cs
index 240358202f..c90058fdac 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0003_NullablePrimaryKey.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0003_NullablePrimaryKey.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.16
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0004_PairAttributeMisusageIsNotHandled.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0004_PairAttributeMisusageIsNotHandled.cs
index f9b4d21bc7..edf4b2e07a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0004_PairAttributeMisusageIsNotHandled.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0004_PairAttributeMisusageIsNotHandled.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.11.26
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0007_InvalidNotNullConstraint.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0007_InvalidNotNullConstraint.cs
index 6fbcf822da..db9e4d0088 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0007_InvalidNotNullConstraint.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0007_InvalidNotNullConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.25
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0009_2SymmetricTablesForMNRelationship.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0009_2SymmetricTablesForMNRelationship.cs
index 484d5683e2..3ccfb70e4f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0009_2SymmetricTablesForMNRelationship.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0009_2SymmetricTablesForMNRelationship.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.26
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0012_TakeSkipSequence.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0012_TakeSkipSequence.cs
index 2d752bb196..c6d1b512de 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0012_TakeSkipSequence.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0012_TakeSkipSequence.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.20
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0013_SqlBuilderRequestTaskBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0013_SqlBuilderRequestTaskBug.cs
index 2c97e9ab7a..af3d0f8971 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0013_SqlBuilderRequestTaskBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0013_SqlBuilderRequestTaskBug.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.20
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0013_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0014_SymmetricRelationshipIsUnsupported.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0014_SymmetricRelationshipIsUnsupported.cs
index 52b643b629..893333f741 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0014_SymmetricRelationshipIsUnsupported.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0014_SymmetricRelationshipIsUnsupported.cs
@@ -5,8 +5,6 @@
 // Created:    2008.11.26
 
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0016_FieldOfInterfaceType.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0016_FieldOfInterfaceType.cs
index 577bf8864a..4b1742e7ef 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0016_FieldOfInterfaceType.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0016_FieldOfInterfaceType.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.12.09
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0016_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0017_ReferentialActionCascade.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0017_ReferentialActionCascade.cs
index 47b47e9a3e..0dd33d8d68 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0017_ReferentialActionCascade.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0017_ReferentialActionCascade.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.12.15
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0017_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0021_InvalidSqlQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0021_InvalidSqlQuery.cs
index a3f1c71dfd..688d6c9008 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0021_InvalidSqlQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0021_InvalidSqlQuery.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.01.19
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0028_1_1SymmetricAssociationBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0028_1_1SymmetricAssociationBug.cs
index de87d91220..df9740a53c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0028_1_1SymmetricAssociationBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0028_1_1SymmetricAssociationBug.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.02.12
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0028_1_1SymmetricAssociationBug_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0036_AutomaticGenericTypesRegistration.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0036_AutomaticGenericTypesRegistration.cs
index 414a70ea5f..829a9501be 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0036_AutomaticGenericTypesRegistration.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0036_AutomaticGenericTypesRegistration.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:  2009.05.13
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0036_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0082_ReferentialManagerProblem.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0082_ReferentialManagerProblem.cs
index 2ecd259e59..12d0a49bc5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0082_ReferentialManagerProblem.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0082_ReferentialManagerProblem.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.04
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0082_ReferentialManagerProblem_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0096_NumerousSchemaExtraction.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0096_NumerousSchemaExtraction.cs
index 8d79fc0f38..64efb8cde4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0096_NumerousSchemaExtraction.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0096_NumerousSchemaExtraction.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.09
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0167_SingleTableProblem.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0167_SingleTableProblem.cs
index 3a4b2da427..2b7dad4b08 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0167_SingleTableProblem.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0167_SingleTableProblem.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.09
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0188_ModelBuilderError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0188_ModelBuilderError.cs
index 554af93826..b9428e1eae 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0188_ModelBuilderError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0188_ModelBuilderError.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.12
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0188_ModelBuilderError_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0245_StructureWhere.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0245_StructureWhere.cs
index 03a73f4e0e..b9bc4421ff 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0245_StructureWhere.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0245_StructureWhere.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.06.25
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0262_StructureAssignment.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0262_StructureAssignment.cs
index 8cd192f80b..fb61045df7 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0262_StructureAssignment.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0262_StructureAssignment.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.29
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0262_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0271_EntityNotInserted.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0271_EntityNotInserted.cs
index a241b7f866..c255aa4623 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0271_EntityNotInserted.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0271_EntityNotInserted.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.07.07
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0276_DuplicateIndex.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0276_DuplicateIndex.cs
index d8c0aaa72d..50c61ef92c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0276_DuplicateIndex.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0276_DuplicateIndex.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.29
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0282_EntitySetContains.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0282_EntitySetContains.cs
index a565b7a2cd..1a0b5f8f0a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0282_EntitySetContains.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0282_EntitySetContains.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.07.10
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0282_EntitySetContains_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0296_DeferredConstraints.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0296_DeferredConstraints.cs
index 90a64a42c4..0efdbdbc8a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0296_DeferredConstraints.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0296_DeferredConstraints.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.07.21
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0296_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0298_InheritedAssociationIsIgnored.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0298_InheritedAssociationIsIgnored.cs
index 0b14e3d879..76edfeab42 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0298_InheritedAssociationIsIgnored.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0298_InheritedAssociationIsIgnored.cs
@@ -4,13 +4,10 @@
 // Created by: a
 // Created:    a
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0298_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0298_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0307_EntitySetOfType.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0307_EntitySetOfType.cs
index 6709e26d23..ead30cb0e9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0307_EntitySetOfType.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0307_EntitySetOfType.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.08.13
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0307_EntitySetOfType_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0331_ForgetHierarchyRoot.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0331_ForgetHierarchyRoot.cs
index 5afaa79f84..bc83ff3470 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0331_ForgetHierarchyRoot.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0331_ForgetHierarchyRoot.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.03
 
-using System;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0331_ForgetHierarchyRoot_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0351_NameBuilderProblem.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0351_NameBuilderProblem.cs
index 2ec228c241..c804da3285 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0351_NameBuilderProblem.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0351_NameBuilderProblem.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.24
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0351_NameBuilderProblem_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0359_UpgradeUsingAutoshortenTransaction.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0359_UpgradeUsingAutoshortenTransaction.cs
index 62aa8ec327..182b9c43f9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0359_UpgradeUsingAutoshortenTransaction.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0359_UpgradeUsingAutoshortenTransaction.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.24
 
-using System;
 using System.Transactions;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0359_CustomSessionConfigurationProblem_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0370_EntitiSetIsNotHandledProperly.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0370_EntitiSetIsNotHandledProperly.cs
index 8619b2fba2..6e38068083 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0370_EntitiSetIsNotHandledProperly.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0370_EntitiSetIsNotHandledProperly.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.03
 
-using System;
 using System.Runtime.Serialization;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0371_ObjectEquals.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0371_ObjectEquals.cs
index 00d6def6b7..c341869a19 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0371_ObjectEquals.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0371_ObjectEquals.cs
@@ -4,12 +4,10 @@
 // Created by: Alexey Gamzov
 // Created:    2009.09.02
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Tests.Issues.Issue0371_ObjectEquals_Model;
-using System.Linq;
 using Xtensive.Orm.Tests.Linq;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0371_ObjectEquals_Model
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0372_SelfReferenceWithInheritance.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0372_SelfReferenceWithInheritance.cs
index 2e1f1f93d2..28e313b5b3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0372_SelfReferenceWithInheritance.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0372_SelfReferenceWithInheritance.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.09.03
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0372_SelfReferenceWithInheritance_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0376_RemoveFieldHint.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0376_RemoveFieldHint.cs
index 35e80c6b20..d65edccedb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0376_RemoveFieldHint.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0376_RemoveFieldHint.cs
@@ -4,15 +4,12 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
 using System.Reflection;
-using System.Linq;
 
 #region Models
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0391_OnRemoveActionNone.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0391_OnRemoveActionNone.cs
index fce25228e6..066face8bb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0391_OnRemoveActionNone.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0391_OnRemoveActionNone.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.21
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0391_OnRemoveActionNone_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0394_UndefinedSqlTypeExtractionError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0394_UndefinedSqlTypeExtractionError.cs
index 3fbb2a9919..160b71a9ef 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0394_UndefinedSqlTypeExtractionError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0394_UndefinedSqlTypeExtractionError.cs
@@ -8,7 +8,6 @@
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
-using System.Linq;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0402_WrongEntitySetQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0402_WrongEntitySetQuery.cs
index de46c13819..a466f60c12 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0402_WrongEntitySetQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0402_WrongEntitySetQuery.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.15
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0402_WrongEntitySetQuery_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference.cs
index 959e099f84..174cb6915e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2009.09.17
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Container.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Container.cs
index 7938405740..3e4940df60 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Container.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Container.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/CreateObjects.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/CreateObjects.cs
index 0d93ddb2d3..d492d616da 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/CreateObjects.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/CreateObjects.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.History.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.History.cs
index 3d622edbb0..f9229dfc5f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.History.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.History.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.cs
index 561f141f3d..65bc831eb1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Document.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/DocumentLink.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/DocumentLink.cs
index b1f933890d..9781b2ed38 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/DocumentLink.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/DocumentLink.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/EchoProcessor.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/EchoProcessor.cs
index d2d441a9b3..00442e02ea 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/EchoProcessor.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/EchoProcessor.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/ErrorDocument.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/ErrorDocument.cs
index d2ec738c17..0ad9876d0a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/ErrorDocument.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/ErrorDocument.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntry.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntry.cs
index c96b7bee5c..c0c1c444f2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntry.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntry.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntryVisibility.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntryVisibility.cs
index cfa3c5950f..90f01bd90f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntryVisibility.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/HistoryEntryVisibility.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Processor.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Processor.cs
index de07652cca..0a2c7e2d5e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Processor.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/Processor.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0408_EntitySetNullReference_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/QueueProcessor.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/QueueProcessor.cs
index 0d575a1587..50df1d6520 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/QueueProcessor.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0408_EntitySetNullReference_Model/QueueProcessor.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0409_ConstructorTransactional.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0409_ConstructorTransactional.cs
index 93a40654ff..0a7e7bca79 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0409_ConstructorTransactional.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0409_ConstructorTransactional.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2009.09.17
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0409_ConstructorTransactional_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0422_GetStructureFieldsForComplexStructures.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0422_GetStructureFieldsForComplexStructures.cs
index 9590eb0c8a..28c4224bbf 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0422_GetStructureFieldsForComplexStructures.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0422_GetStructureFieldsForComplexStructures.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.05
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0424_SqlCommandIsNull.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0424_SqlCommandIsNull.cs
index 84997aecb9..f0eb3e9872 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0424_SqlCommandIsNull.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0424_SqlCommandIsNull.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.08
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0296_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0435_BatchingFail.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0435_BatchingFail.cs
index f6a6085110..0fd3303f9d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0435_BatchingFail.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0435_BatchingFail.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.15
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0435_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0452_OrderByIncorrectColumn.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0452_OrderByIncorrectColumn.cs
index e2937ce564..1cd84b4a15 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0452_OrderByIncorrectColumn.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0452_OrderByIncorrectColumn.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.26
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0457_EntityStateToString.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0457_EntityStateToString.cs
index e3cde5bfa7..9779f4b0b5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0457_EntityStateToString.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0457_EntityStateToString.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.10.29
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0457_EntityStateToStringModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0485_EntitySetDescendant.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0485_EntitySetDescendant.cs
index c6e50a3cfb..b2509fa9e2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0485_EntitySetDescendant.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0485_EntitySetDescendant.cs
@@ -4,14 +4,12 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.26
 
-using System;
 using System.Runtime.Serialization;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.Issues.Issue0485_EntitySetDescendant_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0485_EntitySetDescendant_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0490_GroupByWithTypeId.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0490_GroupByWithTypeId.cs
index 43d100f3c1..21518babe6 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0490_GroupByWithTypeId.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0490_GroupByWithTypeId.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.03
 
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0493_BadImageFormatTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0493_BadImageFormatTest.cs
index c9023b0e87..f4ecc88a81 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0493_BadImageFormatTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0493_BadImageFormatTest.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0493_BadImageFormatTest_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0512_NullableGetValueOrDefaultIsNotSupported.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0512_NullableGetValueOrDefaultIsNotSupported.cs
index e7d26f3cb5..bae17bdd4f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0512_NullableGetValueOrDefaultIsNotSupported.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0512_NullableGetValueOrDefaultIsNotSupported.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.06
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.DbTypeSupportModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0559_EntitySetQueryError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0559_EntitySetQueryError.cs
index 41acd66fab..bbfd950346 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0559_EntitySetQueryError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0559_EntitySetQueryError.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.23
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0559_EntitySetQueryError_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0585_TakeSkipJoinMappingError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0585_TakeSkipJoinMappingError.cs
index 53052e2977..431c32ba4d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0585_TakeSkipJoinMappingError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0585_TakeSkipJoinMappingError.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.19
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0587_ByteArrayEquals.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0587_ByteArrayEquals.cs
index affb479845..7dea8ce208 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0587_ByteArrayEquals.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0587_ByteArrayEquals.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.22
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0587_ByteArrayEquals_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0593_OverrideDefaultSchema.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0593_OverrideDefaultSchema.cs
index 22a7c1be0e..659c037711 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0593_OverrideDefaultSchema.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0593_OverrideDefaultSchema.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.02
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0597_OpenGenericsInDomainModel.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0597_OpenGenericsInDomainModel.cs
index cf8d025c98..91a5529f18 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0597_OpenGenericsInDomainModel.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0597_OpenGenericsInDomainModel.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0597_OpenGenericsInDomainModel_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0624_EntitySetSubqueryError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0624_EntitySetSubqueryError.cs
index ab189164c4..7e5a11b1fb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0624_EntitySetSubqueryError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0624_EntitySetSubqueryError.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0626_SequenceContainsNoElements.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0626_SequenceContainsNoElements.cs
index 8b723b4ae5..40c8950e4d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0626_SequenceContainsNoElements.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0626_SequenceContainsNoElements.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0628_ExecuteFutureScalarError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0628_ExecuteFutureScalarError.cs
index c44076102e..5d49ece81c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0628_ExecuteFutureScalarError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0628_ExecuteFutureScalarError.cs
@@ -4,10 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
 using System.Collections;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Dynamic;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0630_NullReferenceOnSelect.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0630_NullReferenceOnSelect.cs
index e6228df270..2f47f133c7 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0630_NullReferenceOnSelect.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0630_NullReferenceOnSelect.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
 using System.Collections;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0630_NullReferenceOnSelect_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0634_PairToMisuse.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0634_PairToMisuse.cs
index 101402e3d6..ba43477498 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0634_PairToMisuse.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0634_PairToMisuse.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.06.07
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Tests.Issues.Issue0634_PairToMisuse_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0641_GroupBySumError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0641_GroupBySumError.cs
index 634656e92f..b64c52d7ec 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0641_GroupBySumError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0641_GroupBySumError.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0641_GroupBySumError_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0643_EntitySetAddInCtor.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0643_EntitySetAddInCtor.cs
index 3eb4786c7d..d94d973cdd 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0643_EntitySetAddInCtor.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0643_EntitySetAddInCtor.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0643_EntitySetAddInCtor_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0647_WrongLinqQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0647_WrongLinqQuery.cs
index 25242d2c6c..b23a547e4f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0647_WrongLinqQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0647_WrongLinqQuery.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0648_MultiThreadNullReference.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0648_MultiThreadNullReference.cs
index 7be23e85be..4397c3e8fb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0648_MultiThreadNullReference.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0648_MultiThreadNullReference.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.24
 
-using System;
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0648_MultiThreadNullReference_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0676_NonNullableReferenceBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0676_NonNullableReferenceBug.cs
index f947ff766d..fb4bf485e9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0676_NonNullableReferenceBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0676_NonNullableReferenceBug.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0682_FieldInfoIsNullable.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0682_FieldInfoIsNullable.cs
index 6593238a73..24a14000f2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0682_FieldInfoIsNullable.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0682_FieldInfoIsNullable.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.01.19
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0689_WeirdExceptionWhenMissingConnectionInfo.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0689_WeirdExceptionWhenMissingConnectionInfo.cs
index e29c63d1e5..b1f846573d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0689_WeirdExceptionWhenMissingConnectionInfo.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0689_WeirdExceptionWhenMissingConnectionInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.06.08
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0690_RemoveAndCreate.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0690_RemoveAndCreate.cs
index 74b2b6943f..ac86b121ac 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0690_RemoveAndCreate.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0690_RemoveAndCreate.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.06.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issue0690_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0696_EntitySetItemAddBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0696_EntitySetItemAddBug.cs
index a6b23ad3ca..f49598fd81 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0696_EntitySetItemAddBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0696_EntitySetItemAddBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0713_InconsistentDefaultDateTimeValues.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0713_InconsistentDefaultDateTimeValues.cs
index aeb9998633..50cad7375d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0713_InconsistentDefaultDateTimeValues.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0713_InconsistentDefaultDateTimeValues.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.06.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0715_NestedTypeBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0715_NestedTypeBug.cs
index 85b20e79fd..36b0d397fa 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0715_NestedTypeBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0715_NestedTypeBug.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0717_VersionCheckBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0717_VersionCheckBug.cs
index 9725fe9e07..e2131c89db 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0717_VersionCheckBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0717_VersionCheckBug.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
-using System.Collections.Generic;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0733_UseINNER_JOIN.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0733_UseINNER_JOIN.cs
index 1329ee61b7..b3216c23f1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0733_UseINNER_JOIN.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0733_UseINNER_JOIN.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.12
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0737_PersistentFieldState_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0737_PersistentFieldState.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0737_PersistentFieldState.cs
index 9ba88d542e..4c88d8914a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0737_PersistentFieldState.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0737_PersistentFieldState.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.12
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0733_UseINNER_JOIN_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0751_EntitySetEquals.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0751_EntitySetEquals.cs
index 1606457fc5..c1c508e7af 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0751_EntitySetEquals.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0751_EntitySetEquals.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.08.31
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Issue0754_CopyFieldHint_MoveFieldHint.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Issue0754_CopyFieldHint_MoveFieldHint.cs
index e35de1f92c..bb8d0c0f04 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Issue0754_CopyFieldHint_MoveFieldHint.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Issue0754_CopyFieldHint_MoveFieldHint.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2010.11.17
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion1.cs
index 3b8d50b89c..eef6e02c17 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2010.11.17
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0754_CopyFieldHint_MoveFieldHint.ModelVersion1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion2.cs
index 28b4c41111..9935bc246e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/ModelVersion2.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2010.11.17
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0754_CopyFieldHint_MoveFieldHint.ModelVersion2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Upgrader.cs
index 423830c279..38719c850d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0754_CopyFieldHint_MoveFieldHint/Upgrader.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2010.11.17
 
-using System.Collections.Generic;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Tests.Issues.Issue0754_CopyFieldHint_MoveFieldHint
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0764_LinqTranslationError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0764_LinqTranslationError.cs
index 0c6037b2fc..a46d7dce06 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0764_LinqTranslationError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0764_LinqTranslationError.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.12
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0764_LinqTranslationError_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0765_LinqTranslationError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0765_LinqTranslationError.cs
index 50a648679b..36b33ffce4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0765_LinqTranslationError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0765_LinqTranslationError.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.23
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0765_LinqTranslationError_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0766_LinqTranslationError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0766_LinqTranslationError.cs
index 4cdf0ad986..aaed3e02b9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0766_LinqTranslationError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0766_LinqTranslationError.cs
@@ -4,10 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.23
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0767_QueryByInterfaceException.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0767_QueryByInterfaceException.cs
index c3eb465197..ad25448c10 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0767_QueryByInterfaceException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0767_QueryByInterfaceException.cs
@@ -4,10 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.26
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Tests.Issues.Issue0767_QueryByInterfaceException_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0768_WrongJoinBehavior.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0768_WrongJoinBehavior.cs
index 4415c9f4af..bf307d777b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0768_WrongJoinBehavior.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0768_WrongJoinBehavior.cs
@@ -4,11 +4,9 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.26
 
-using System;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Tests.Issues.Issue0768_WrongJoinBehavior_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0771_AbstractTypeRegistration.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0771_AbstractTypeRegistration.cs
index 5daddc630a..7e2a578a58 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0771_AbstractTypeRegistration.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0771_AbstractTypeRegistration.cs
@@ -4,11 +4,9 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.26
 
-using System;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Tests.Issues.Issue0771_AbstractTypeRegistration_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0773_UnableTranslateUnionQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0773_UnableTranslateUnionQuery.cs
index 61b7800f9e..8aa54d26a5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0773_UnableTranslateUnionQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0773_UnableTranslateUnionQuery.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.11
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0775_WrongLinqQueryOverComputedFields.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0775_WrongLinqQueryOverComputedFields.cs
index 39ae5e5e80..6bd872ed42 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0775_WrongLinqQueryOverComputedFields.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0775_WrongLinqQueryOverComputedFields.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.13
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0776_OrderingCorrectorOfAggregateProvider.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0776_OrderingCorrectorOfAggregateProvider.cs
index 71ccacafc6..c3ddf3a5e8 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0776_OrderingCorrectorOfAggregateProvider.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0776_OrderingCorrectorOfAggregateProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.13
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0777_WrongLinqQueryConditional.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0777_WrongLinqQueryConditional.cs
index e79d28c3bf..fdd9507643 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0777_WrongLinqQueryConditional.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0777_WrongLinqQueryConditional.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.13
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0777_WrongLinqQueryConditional_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0785_GenericStructureBugs.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0785_GenericStructureBugs.cs
index 3edfa8be3e..e9053dc5e9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0785_GenericStructureBugs.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0785_GenericStructureBugs.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0788_EntityIsDetached.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0788_EntityIsDetached.cs
index 8e3c492dcb..562680b6de 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0788_EntityIsDetached.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0788_EntityIsDetached.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.08.27
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0788_EntityIsDetached_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0792_OrderByWithDistinct.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0792_OrderByWithDistinct.cs
index a0248667ed..ed60217d39 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0792_OrderByWithDistinct.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0792_OrderByWithDistinct.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0800_OrderByEnum.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0800_OrderByEnum.cs
index 1f5106e558..4f2c201f48 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0800_OrderByEnum.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0800_OrderByEnum.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0806_ColumnNamingError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0806_ColumnNamingError.cs
index 00638b1ab1..6b1e977f7b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0806_ColumnNamingError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0806_ColumnNamingError.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0808_StructSerialization.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0808_StructSerialization.cs
index 3135b9554b..bb1f894335 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0808_StructSerialization.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0808_StructSerialization.cs
@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0813_AuxilaryTableMappingNameBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0813_AuxilaryTableMappingNameBug.cs
index 7bd5c42bca..de3690f89f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0813_AuxilaryTableMappingNameBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0813_AuxilaryTableMappingNameBug.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.10.27
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0813_AuxilaryTableMappingNameBug_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0817_LocalCollectionWithEnum.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0817_LocalCollectionWithEnum.cs
index b949fc67a5..50651522f1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0817_LocalCollectionWithEnum.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0817_LocalCollectionWithEnum.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues_Issue0817_LocalCollectionWithEnum;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0818_NanosecondTrancation.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0818_NanosecondTrancation.cs
index bd68a0ca5d..0eb37f9234 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0818_NanosecondTrancation.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0818_NanosecondTrancation.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.10.14
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0818_NanosecondTrancation_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0820_GroupByWithDatePart.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0820_GroupByWithDatePart.cs
index 66beecebb2..1ecd592ebd 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0820_GroupByWithDatePart.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0820_GroupByWithDatePart.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues_Issue0820_GroupByWithDatePart;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0821_StructureNulComparisonInLinq.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0821_StructureNulComparisonInLinq.cs
index 69639b3ff7..b25ab9c475 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0821_StructureNulComparisonInLinq.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0821_StructureNulComparisonInLinq.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0825_StrangeLinqBehavior.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0825_StrangeLinqBehavior.cs
index 283aa5ede4..59a24b3880 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0825_StrangeLinqBehavior.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0825_StrangeLinqBehavior.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2010.10.07
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0826_OperandTypeClash.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0826_OperandTypeClash.cs
index 6c9786a1aa..afd21b83cb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0826_OperandTypeClash.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0826_OperandTypeClash.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0827_LinqDtoMaterialization.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0827_LinqDtoMaterialization.cs
index 3a7f5ceacf..20667329ed 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0827_LinqDtoMaterialization.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0827_LinqDtoMaterialization.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2010.10.08
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues_Issue0827_LinqDtoMaterialization;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0828_LinqMaterializeException.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0828_LinqMaterializeException.cs
index 7a12a1fe2c..2ffd25edfd 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0828_LinqMaterializeException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0828_LinqMaterializeException.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2010.10.11
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0835_QueryNestedTooDeep.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0835_QueryNestedTooDeep.cs
index 0f6cd8c643..8f1059bc17 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0835_QueryNestedTooDeep.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0835_QueryNestedTooDeep.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues_Issue0835_QueryNestedTooDeep;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0839_MultithreadingBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0839_MultithreadingBug.cs
index 72b836ec2e..56682effe1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0839_MultithreadingBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0839_MultithreadingBug.cs
@@ -4,10 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.10.14
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0839_MultithreadingBug_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0844_GroupByConstant.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0844_GroupByConstant.cs
index ef0776b1b3..408d0bf1e9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0844_GroupByConstant.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0844_GroupByConstant.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0845_KeyTypeAccessBug.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0845_KeyTypeAccessBug.cs
index 3ff2837a87..18d1e88360 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0845_KeyTypeAccessBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0845_KeyTypeAccessBug.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.10.27
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0847_IsOperator.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0847_IsOperator.cs
index 5efcbc6255..58f63e6501 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0847_IsOperator.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0847_IsOperator.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues_Issue0847_IsOperator;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0851_AnyMappingError.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0851_AnyMappingError.cs
index 64f8c8a644..2b7911dae4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0851_AnyMappingError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0851_AnyMappingError.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2010.10.22
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0851_AnyMappingError_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue0860_DateTimeDate.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue0860_DateTimeDate.cs
index 9fa9b6ef49..a2f35c5404 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue0860_DateTimeDate.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue0860_DateTimeDate.cs
@@ -1,11 +1,9 @@
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Tests.Issues.Issue0860_DateTimeDateModel;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue679,681_EntitySetRelatedBugs.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue679,681_EntitySetRelatedBugs.cs
index 715c0f832a..3fe5bdb623 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue679,681_EntitySetRelatedBugs.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue679,681_EntitySetRelatedBugs.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.01.19
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA363_WrongInnerJoin.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA363_WrongInnerJoin.cs
index 3f9e704562..560987073d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA363_WrongInnerJoin.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA363_WrongInnerJoin.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.01.21
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueA363_WrongInnerJoin_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA399_SetPropertyForPrivatePropertiesOfInheritors.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA399_SetPropertyForPrivatePropertiesOfInheritors.cs
index 20befbc671..822f8a5b0e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA399_SetPropertyForPrivatePropertiesOfInheritors.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA399_SetPropertyForPrivatePropertiesOfInheritors.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.07
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA401_AmbiguousMatchFoundException.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA401_AmbiguousMatchFoundException.cs
index a5132b87e0..2b7c7e4461 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA401_AmbiguousMatchFoundException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA401_AmbiguousMatchFoundException.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.07
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueA401_AmbiguousMatchFoundException_Model;
-using System.Linq;
 using Xtensive.Orm.Validation;
 
 namespace Xtensive.Orm.Tests.Issues
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA408_TargetException.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA408_TargetException.cs
index a1500bff4f..836c8e98ab 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA408_TargetException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA408_TargetException.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.07
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA413_KeyNotFoundException.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA413_KeyNotFoundException.cs
index 1ddce41f18..c1c3b7cff2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA413_KeyNotFoundException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA413_KeyNotFoundException.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.02
 
-using System;
-using System.Linq;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA418_UnableToCompileModelWithPersistentInterface.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA418_UnableToCompileModelWithPersistentInterface.cs
index 89e8dbcbe0..8a2060447c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA418_UnableToCompileModelWithPersistentInterface.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA418_UnableToCompileModelWithPersistentInterface.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.08
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueA418_UnableToCompileModelWithPersistentInterface_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueA424_QueryByInterfaceException.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueA424_QueryByInterfaceException.cs
index b37dbde4ef..a6da812e7e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueA424_QueryByInterfaceException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueA424_QueryByInterfaceException.cs
@@ -4,13 +4,11 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.17
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Tests.Issues.IssueA424_QueryByInterfaceException_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0070_IncludeProviderParameterConflictWithinParameterContext.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0070_IncludeProviderParameterConflictWithinParameterContext.cs
index 79ae8fd5cb..4d89becc96 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0070_IncludeProviderParameterConflictWithinParameterContext.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0070_IncludeProviderParameterConflictWithinParameterContext.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0110_SimpleCommandProcessorOverridesOriginalException.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0110_SimpleCommandProcessorOverridesOriginalException.cs
index 2c0243adb5..44e0ce6c4c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0110_SimpleCommandProcessorOverridesOriginalException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0110_SimpleCommandProcessorOverridesOriginalException.cs
@@ -2,12 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0132_IncorrectInsertForSingleTableHierarchy.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0132_IncorrectInsertForSingleTableHierarchy.cs
index 10f8bde7c0..7229e66a38 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0132_IncorrectInsertForSingleTableHierarchy.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub0132_IncorrectInsertForSingleTableHierarchy.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub071_DataReaderRemainsOpen.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub071_DataReaderRemainsOpen.cs
index bb751ad24a..a48c2fef0e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub071_DataReaderRemainsOpen.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGitHub071_DataReaderRemainsOpen.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueGitHub071_DataReaderRemainsOpenModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0048_CoalesceReturnsWrongResults.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0048_CoalesceReturnsWrongResults.cs
index d317774031..a58d56b759 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0048_CoalesceReturnsWrongResults.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0048_CoalesceReturnsWrongResults.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0114_QueryRootReuseCauseNoRefJoin.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0114_QueryRootReuseCauseNoRefJoin.cs
index 007c8748da..c9d9b34129 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0114_QueryRootReuseCauseNoRefJoin.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0114_QueryRootReuseCauseNoRefJoin.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0149_ParameterReplacerHandlesNullConstsIncorrectly.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0149_ParameterReplacerHandlesNullConstsIncorrectly.cs
index dba087e74f..0caa11866c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0149_ParameterReplacerHandlesNullConstsIncorrectly.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0149_ParameterReplacerHandlesNullConstsIncorrectly.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0164_ClosureReplacementForDescendantTypes.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0164_ClosureReplacementForDescendantTypes.cs
index e525fc0b56..0e90b6ab1f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0164_ClosureReplacementForDescendantTypes.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0164_ClosureReplacementForDescendantTypes.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0171_ReadDateTimeOffsetFromPackedTuple.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0171_ReadDateTimeOffsetFromPackedTuple.cs
index 25c8fc0aef..04d5c78b9a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0171_ReadDateTimeOffsetFromPackedTuple.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0171_ReadDateTimeOffsetFromPackedTuple.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueGithub0171_ReadDateTimeOffsetFromPackedTupleModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0224_DelayedQueryCapture.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0224_DelayedQueryCapture.cs
index 56ae7c26a1..8168d84565 100755
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0224_DelayedQueryCapture.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub0224_DelayedQueryCapture.cs
@@ -2,13 +2,10 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Dynamic;
 using System.Reflection;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Caching;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub312_DefaultExpressionProblem.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub312_DefaultExpressionProblem.cs
index af72111a63..702c58a395 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueGithub312_DefaultExpressionProblem.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueGithub312_DefaultExpressionProblem.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0003_OrderByStructureFieldLost.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0003_OrderByStructureFieldLost.cs
index 9cf096da45..e89f18f4ac 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0003_OrderByStructureFieldLost.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0003_OrderByStructureFieldLost.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2011.03.05
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJIRA0003_OrderByStructureFieldLost_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0020_CustomLINQCompilerContainerInterface.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0020_CustomLINQCompilerContainerInterface.cs
index 385dc1d85d..b2860c81a7 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0020_CustomLINQCompilerContainerInterface.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0020_CustomLINQCompilerContainerInterface.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.03.03
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0036_AutoTransactionsOpenModeDoesNotWork.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0036_AutoTransactionsOpenModeDoesNotWork.cs
index 46ab2d31e4..835604bb5e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0036_AutoTransactionsOpenModeDoesNotWork.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0036_AutoTransactionsOpenModeDoesNotWork.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.03.14
 
-using System;
 using System.ComponentModel;
 using System.Diagnostics;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0085.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0085.cs
index f33270ae4e..e091b65d25 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0085.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJIRA0085.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.04.28
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJIRA0085_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0042_IndexAttributeIsOmitted.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0042_IndexAttributeIsOmitted.cs
index 317f1e81bb..6633c43f74 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0042_IndexAttributeIsOmitted.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0042_IndexAttributeIsOmitted.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.10
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0042_IndexAttributeIsOmitted_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0071_DistinctDoesNotWorkProperly.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0071_DistinctDoesNotWorkProperly.cs
index 57745a1342..c079a37129 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0071_DistinctDoesNotWorkProperly.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0071_DistinctDoesNotWorkProperly.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.25
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0071_DistinctDoesNotWorkProperlyModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0083_DtoMaterialization.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0083_DtoMaterialization.cs
index 4ee06e5e9c..286f821667 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0083_DtoMaterialization.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0083_DtoMaterialization.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.04.26
 
-using System.Linq;
 using System.Linq.Dynamic;
 using NUnit.Framework;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0102_NoForeignKeyOnInterfaceField.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0102_NoForeignKeyOnInterfaceField.cs
index 4b7a5115cc..9709e691b5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0102_NoForeignKeyOnInterfaceField.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0102_NoForeignKeyOnInterfaceField.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.11
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue0102_NoForeignKeyOnInterfaceField_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexes.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexes.cs
index aa6e8cd193..d007e315da 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexes.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexes.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0116_InterfacesCastAndIndexesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Generated.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Generated.cs
index caef6da700..6460d1deb9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Generated.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Generated.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0116_InterfacesCastAndIndexesModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/IRecord.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/IRecord.cs
index 5a9557bc6f..145fdab3ca 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/IRecord.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/IRecord.cs
@@ -1,4 +1,3 @@
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0116_InterfacesCastAndIndexesModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Record.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Record.cs
index 128e56960d..6c7fb03810 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Record.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0116_InterfacesCastAndIndexesModel/Record.cs
@@ -1,4 +1,3 @@
-using System;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0116_InterfacesCastAndIndexesModel
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0117_FKStructureTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0117_FKStructureTest.cs
index 7e60143b29..8d4e5de7e9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0117_FKStructureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0117_FKStructureTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.05.19
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.MultipleFKViaStructureTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0149_LinqTranslationError.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0149_LinqTranslationError.cs
index 4b37b6abcf..19669a18db 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0149_LinqTranslationError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0149_LinqTranslationError.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.06.21
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0171_DateTimeOffset.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0171_DateTimeOffset.cs
index bff99b870d..5a3fce13ab 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0171_DateTimeOffset.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0171_DateTimeOffset.cs
@@ -4,8 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2013.11.27
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0179_NullableBooleanFieldsQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0179_NullableBooleanFieldsQuery.cs
index 6f561408ca..ebcd8fd0dc 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0179_NullableBooleanFieldsQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0179_NullableBooleanFieldsQuery.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.23
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0179_NullableBooleanFieldsQueryModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion1.cs
index 803315a881..90d67a9475 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.19
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0180_ChangeNullabilityViaUpgradeHints.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion2.cs
index 8725c85a0e..2ff7cdd39b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/ModelVersion2.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.19
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0180_ChangeNullabilityViaUpgradeHints.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/UpgradeTest.cs
index 61df2fbad7..884039a9c9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.19
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/Upgrader.cs
index 8247a3ed75..d1cfae2a46 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0180_ChangeNullabilityViaUpgradeHints/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.19
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0187_TypeCastInContain.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0187_TypeCastInContain.cs
index 0820dc8e8d..c2fb1d65b9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0187_TypeCastInContain.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0187_TypeCastInContain.cs
@@ -4,11 +4,9 @@
 // Created by: Dmitri Maximov
 // Created:    2011.09.06
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue_TypeCastInContain_Model;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_TypeCastInContain_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0188_MissingFKsForComplexHierarchies.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0188_MissingFKsForComplexHierarchies.cs
index 8f100cd395..3d0bbeb1ab 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0188_MissingFKsForComplexHierarchies.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0188_MissingFKsForComplexHierarchies.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.20
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0194_WrongResultWhenInClauseArgumentIsEmpty.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0194_WrongResultWhenInClauseArgumentIsEmpty.cs
index 56392fa48e..e8cde92bcf 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0194_WrongResultWhenInClauseArgumentIsEmpty.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0194_WrongResultWhenInClauseArgumentIsEmpty.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.22
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0195_DeleteAndCreateWithValidation.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0195_DeleteAndCreateWithValidation.cs
index 46ac76c836..61609ef48e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0195_DeleteAndCreateWithValidation.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0195_DeleteAndCreateWithValidation.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.23
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0195_DeleteAndCreateWithValidationModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0196_GuidAsTypeDiscriminator.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0196_GuidAsTypeDiscriminator.cs
index e4b36b98bd..fd2131f16f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0196_GuidAsTypeDiscriminator.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0196_GuidAsTypeDiscriminator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.27
 
-using System;
 using NUnit.Framework;
 using Xtensive.Reflection;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0202_OnRemoveActionOverriding.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0202_OnRemoveActionOverriding.cs
index 823180d546..abfa5daa5d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0202_OnRemoveActionOverriding.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0202_OnRemoveActionOverriding.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.11.18
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0202_OnRemoveActionOverriding_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion1.cs
index 34b9bea2cc..bac7dc62eb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0208_IncorrectUpgradeSequence.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion2.cs
index 39f833413d..dc4f394cc5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0208_IncorrectUpgradeSequence.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/UpgradeTest.cs
index 87d6d3e095..08fd6233da 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/Upgrader.cs
index 3d53cff379..5d495db6bd 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0208_IncorrectUpgradeSequence/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0213_GroupByNewDate.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0213_GroupByNewDate.cs
index 11c4586cf2..b8084b5659 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0213_GroupByNewDate.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0213_GroupByNewDate.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.25
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0213_GroupByNewDateModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0221_UnableToTranslateAggregate.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0221_UnableToTranslateAggregate.cs
index a467bd0a8a..6cbdfd7ce8 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0221_UnableToTranslateAggregate.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0221_UnableToTranslateAggregate.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.21
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0222_GroupByBooleanColumn.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0222_GroupByBooleanColumn.cs
index bd74201045..59019d678f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0222_GroupByBooleanColumn.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0222_GroupByBooleanColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.22
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0222_GroupByBooleanColumnModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0232_SupportForEnumHasFlag.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0232_SupportForEnumHasFlag.cs
index aadd67065c..923a22b77c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0232_SupportForEnumHasFlag.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0232_SupportForEnumHasFlag.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.07.22
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0232_SupportForEnumHasFlageModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0238_GroupByGeneric.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0238_GroupByGeneric.cs
index 34a364427d..2c3c4fea9d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0238_GroupByGeneric.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0238_GroupByGeneric.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.24
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueIssueJira0238_GroupByGenericModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0240_SortingInSubqueryIsOmitted.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0240_SortingInSubqueryIsOmitted.cs
index 7555d67d81..fc3a753efe 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0240_SortingInSubqueryIsOmitted.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0240_SortingInSubqueryIsOmitted.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.25
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0242_LegacyExecuteMethodsDoNotWork.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0242_LegacyExecuteMethodsDoNotWork.cs
index cabf0cd5c5..0b66cb1c05 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0242_LegacyExecuteMethodsDoNotWork.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0242_LegacyExecuteMethodsDoNotWork.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.27
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using MetadataType = Xtensive.Orm.Metadata.Type;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0243_PrefetchSyntaxSugar.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0243_PrefetchSyntaxSugar.cs
index 19bceedd66..816f64581b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0243_PrefetchSyntaxSugar.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0243_PrefetchSyntaxSugar.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.30
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0243_PrefetchSyntaxSugarModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0261_QuerySingleInsideDelayedCompiledQueries.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0261_QuerySingleInsideDelayedCompiledQueries.cs
index 7083db1908..82b590f214 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0261_QuerySingleInsideDelayedCompiledQueries.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0261_QuerySingleInsideDelayedCompiledQueries.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.07.28
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0261_QuerySingleInsideDelayedCompiledQueriesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0275_FilterComputedColumn.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0275_FilterComputedColumn.cs
index 2b092bd2c9..037e1827d1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0275_FilterComputedColumn.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0275_FilterComputedColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.31
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0275_FilterComputedColumnModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0314_IncorrectTransactionDisposing.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0314_IncorrectTransactionDisposing.cs
index 4368134580..56bce81c8e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0314_IncorrectTransactionDisposing.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0314_IncorrectTransactionDisposing.cs
@@ -1,6 +1,3 @@
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0330_MaterializationOfNullReference.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0330_MaterializationOfNullReference.cs
index e44dce7c0c..e0a1bbdf40 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0330_MaterializationOfNullReference.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0330_MaterializationOfNullReference.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.17
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0330_MaterializationOfNullReferenceModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0339_PrefetchViaStructure.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0339_PrefetchViaStructure.cs
index 2fa48277c2..d1e474b98a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0339_PrefetchViaStructure.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0339_PrefetchViaStructure.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.22
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Issues.IssueJira0339_PrefetchViaStructureModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0346_OptimizeSessionSaveChangesWithoutInboundOnlyAndOutboundOnly.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0346_OptimizeSessionSaveChangesWithoutInboundOnlyAndOutboundOnly.cs
index 3d498685f9..98fe8636d8 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0346_OptimizeSessionSaveChangesWithoutInboundOnlyAndOutboundOnly.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0346_OptimizeSessionSaveChangesWithoutInboundOnlyAndOutboundOnly.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.07.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0357_IndexWithInheritedFields.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0357_IndexWithInheritedFields.cs
index abd33ac8bf..da69eb6f0a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0357_IndexWithInheritedFields.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0357_IndexWithInheritedFields.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.08.07
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0385_OracleExtractorFailure.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0385_OracleExtractorFailure.cs
index 0ea4db1c6a..f3f92ca5d5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0385_OracleExtractorFailure.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0385_OracleExtractorFailure.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.18
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0385Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlBox.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlBox.cs
index 9df930f4d9..50732bc5d6 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlBox.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlBox.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.05
 
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlCircle.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlCircle.cs
index eb2a03d709..af3b7833bd 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlCircle.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlCircle.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.06
 
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlLSeg.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlLSeg.cs
index b051b5d3f2..f4b24e0d9c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlLSeg.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlLSeg.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.06
 
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPath.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPath.cs
index 314d2b723e..cfac694a55 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPath.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPath.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.06
 
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPoint.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPoint.cs
index 4b00ec5438..63cdcd5cef 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPoint.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPoint.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.05
 
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPolygon.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPolygon.cs
index 739741ef58..3f8892b0ea 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPolygon.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0416_NpgsqlPolygon.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.06
 
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0421_DateTimeAddXxx.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0421_DateTimeAddXxx.cs
index fcfe848da6..7b878cad88 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0421_DateTimeAddXxx.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0421_DateTimeAddXxx.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.02.14
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0424_DateTimeOperationInvalidSql.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0424_DateTimeOperationInvalidSql.cs
index 46d1e1762c..a39ef3f611 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0424_DateTimeOperationInvalidSql.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0424_DateTimeOperationInvalidSql.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.01.31
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0424_DateTimeOperationInvalidSqlModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0425_DateTimeOperationError.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0425_DateTimeOperationError.cs
index a4b93fd633..8a21e565b4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0425_DateTimeOperationError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0425_DateTimeOperationError.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.01.31
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0425_DateTimeOperationErrorModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0427_IndexOutOfRangeOnContainsOperation.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0427_IndexOutOfRangeOnContainsOperation.cs
index b0c76fb7bf..ffa8b3df9b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0427_IndexOutOfRangeOnContainsOperation.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0427_IndexOutOfRangeOnContainsOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.01.31
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0427_IndexOutOfRangeOnContainsOperationModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0430_PartialIndexOnBoolOrEnumFields.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0430_PartialIndexOnBoolOrEnumFields.cs
index 358d2f3f11..15c3f64cfa 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0430_PartialIndexOnBoolOrEnumFields.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0430_PartialIndexOnBoolOrEnumFields.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.01.31
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0431_IGroupingKeyIsNotUsable.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0431_IGroupingKeyIsNotUsable.cs
index 98e99afc6e..6fe77884ec 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0431_IGroupingKeyIsNotUsable.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0431_IGroupingKeyIsNotUsable.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.01.31
 
-using System;
-using System.Linq;
 using System.Runtime.Serialization;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0432_EnumTypeDiscriminator.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0432_EnumTypeDiscriminator.cs
index 2989886e4b..2075bec9b1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0432_EnumTypeDiscriminator.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0432_EnumTypeDiscriminator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.02.11
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0432_EnumTypeDiscriminatorModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0433_CompiledQueryOverEntitySet.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0433_CompiledQueryOverEntitySet.cs
index f333e72305..b088f5df48 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0433_CompiledQueryOverEntitySet.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0433_CompiledQueryOverEntitySet.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.02.13
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0433_CompiledQueryOverEntitySetModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0437_OperationsWithListOfInt.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0437_OperationsWithListOfInt.cs
index 5074aa50f9..bb1db461fc 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0437_OperationsWithListOfInt.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0437_OperationsWithListOfInt.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.02.22
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0440_CustomCompilerLoosesImplicitCastToNullable.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0440_CustomCompilerLoosesImplicitCastToNullable.cs
index e0c9593010..4e888bec6e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0440_CustomCompilerLoosesImplicitCastToNullable.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0440_CustomCompilerLoosesImplicitCastToNullable.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0441_EntitySetQueryFailsToTranslate.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0441_EntitySetQueryFailsToTranslate.cs
index bcce7e6321..02f9eb20ee 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0441_EntitySetQueryFailsToTranslate.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0441_EntitySetQueryFailsToTranslate.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.04.01
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0441_EntitySetQueryFailsToTranslateModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0442_AsQueryableExpressionInQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0442_AsQueryableExpressionInQuery.cs
index bdcf925553..92b52175ad 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0442_AsQueryableExpressionInQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0442_AsQueryableExpressionInQuery.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.04.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0443_FirstOrDefaultInSubqueryUsesWrongDefault.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0443_FirstOrDefaultInSubqueryUsesWrongDefault.cs
index abd1db497b..642b1ed6d1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0443_FirstOrDefaultInSubqueryUsesWrongDefault.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0443_FirstOrDefaultInSubqueryUsesWrongDefault.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.04.30
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0445_QueryForEntityWithEnumKey.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0445_QueryForEntityWithEnumKey.cs
index 7e98df378a..5f749b478b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0445_QueryForEntityWithEnumKey.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0445_QueryForEntityWithEnumKey.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.05.21
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0445_QueryForEntityWithEnumKeyModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0446_TypeAsOnSubqueryOperand.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0446_TypeAsOnSubqueryOperand.cs
index 92df577b74..f3011752ec 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0446_TypeAsOnSubqueryOperand.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0446_TypeAsOnSubqueryOperand.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.06.25
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_RenameTableInNonDefaultDatabase.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_RenameTableInNonDefaultDatabase.cs
index 90191ea86d..3fd22980b6 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_RenameTableInNonDefaultDatabase.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_RenameTableInNonDefaultDatabase.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.07.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Storage.Multimapping;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_TimeSpanMinMaxValue.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_TimeSpanMinMaxValue.cs
index b275ae918b..fb3f95766c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_TimeSpanMinMaxValue.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0449_TimeSpanMinMaxValue.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.07.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0449_TimeSpanMinMaxValueModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0459_SelfReferencingEntitiesRemove.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0459_SelfReferencingEntitiesRemove.cs
index 82b4bd2dc7..d9d2bb64e5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0459_SelfReferencingEntitiesRemove.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0459_SelfReferencingEntitiesRemove.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.14
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0459_SelfReferencingEntitiesRemoveModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0471_LikeOperatorSupport.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0471_LikeOperatorSupport.cs
index 49f0619b96..f1a6d8871d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0471_LikeOperatorSupport.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0471_LikeOperatorSupport.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.12
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0471_LikeOperatorSupportModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0481_EntitySetCachesInvalidState.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0481_EntitySetCachesInvalidState.cs
index 882ff5ef77..bcd5a7c107 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0481_EntitySetCachesInvalidState.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0481_EntitySetCachesInvalidState.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.17
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0481_EntitySetCachesInvalidStateModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0500_OptimizeMultipleAggregatesWithProjections.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0500_OptimizeMultipleAggregatesWithProjections.cs
index 93dc316040..5727824571 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0500_OptimizeMultipleAggregatesWithProjections.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0500_OptimizeMultipleAggregatesWithProjections.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.10
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Rewriters;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0516_PartialIndexConstruction.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0516_PartialIndexConstruction.cs
index 50d9843aab..5a69a37845 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0516_PartialIndexConstruction.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0516_PartialIndexConstruction.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.02.13
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0519_StaleKeyInEntitySet.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0519_StaleKeyInEntitySet.cs
index ffb45ad440..9fbfaad054 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0519_StaleKeyInEntitySet.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0519_StaleKeyInEntitySet.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.02.09
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0519_StaleKeyInEntitySetModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0528_LongEnumBitOperations.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0528_LongEnumBitOperations.cs
index ad6a97259d..d73d37e64e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0528_LongEnumBitOperations.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0528_LongEnumBitOperations.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.04.11
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Issues.IssueJira0528_LongEnumBitOperationsModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0529_MultipleInOperations.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0529_MultipleInOperations.cs
index 6736f1d693..e96a3d0486 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0529_MultipleInOperations.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0529_MultipleInOperations.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.05.21
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Issues.IssueJira0529_MultipleInOperationsTestModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0531_IncorrectNameOfRecycledNestedType.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0531_IncorrectNameOfRecycledNestedType.cs
index d5d59b18b6..2523c71afd 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0531_IncorrectNameOfRecycledNestedType.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0531_IncorrectNameOfRecycledNestedType.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.05.21
 
-using System;
 using NUnit.Framework;
 using model1 = Xtensive.Orm.Tests.Issues.IssueJira0529_BugWithRecycledNestedV1;
 using model2 = Xtensive.Orm.Tests.Issues.IssueJira0529_BugWithRecycledNestedV2;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0537_DropDefaultConstraintBugTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0537_DropDefaultConstraintBugTest.cs
index 20dd741c45..552392f3bc 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0537_DropDefaultConstraintBugTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0537_DropDefaultConstraintBugTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.12.30
 
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0538_IncorrectSortedActionSequence.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0538_IncorrectSortedActionSequence.cs
index 6a9d1f7642..bb4126d17a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0538_IncorrectSortedActionSequence.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0538_IncorrectSortedActionSequence.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.06.05
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Issues.IssueJira0538_IncorrectSortedActionSequenceModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0540_IncorrectBehaviorOnDomainUpgradeWithRecycledTypeBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0540_IncorrectBehaviorOnDomainUpgradeWithRecycledTypeBug.cs
index c85f8ec52b..add5dee2df 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0540_IncorrectBehaviorOnDomainUpgradeWithRecycledTypeBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0540_IncorrectBehaviorOnDomainUpgradeWithRecycledTypeBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.06.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0542_OfTypeTranslationBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0542_OfTypeTranslationBug.cs
index 98758984aa..1a1c8ff4e3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0542_OfTypeTranslationBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0542_OfTypeTranslationBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.07.25
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0546_IncorrectCachingOfQueries.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0546_IncorrectCachingOfQueries.cs
index 7d7a2c9fdf..ffe8c5d287 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0546_IncorrectCachingOfQueries.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0546_IncorrectCachingOfQueries.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.08.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0550_IncorrectJoinSequenceTranslationInMySqlTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0550_IncorrectJoinSequenceTranslationInMySqlTest.cs
index 530c356d73..d33b3381b6 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0550_IncorrectJoinSequenceTranslationInMySqlTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0550_IncorrectJoinSequenceTranslationInMySqlTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.09.01
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0550_IncorrectJoinSequenceTranslationInMySqlTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0553_IncorrectLeftJoinOnNotNullEntityField.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0553_IncorrectLeftJoinOnNotNullEntityField.cs
index 3356de0776..e92e0ca5b6 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0553_IncorrectLeftJoinOnNotNullEntityField.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0553_IncorrectLeftJoinOnNotNullEntityField.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.09.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0556_ArithmeticExceptionWhenSubstractionOfDates.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0556_ArithmeticExceptionWhenSubstractionOfDates.cs
index 6b272011b7..555b7fb8c9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0556_ArithmeticExceptionWhenSubstractionOfDates.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0556_ArithmeticExceptionWhenSubstractionOfDates.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.26
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0557_RollbackOfDifferentialTupleDifferenceWhenPersistFailed.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0557_RollbackOfDifferentialTupleDifferenceWhenPersistFailed.cs
index aff90a6632..9264ff2075 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0557_RollbackOfDifferentialTupleDifferenceWhenPersistFailed.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0557_RollbackOfDifferentialTupleDifferenceWhenPersistFailed.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2014.10.03
 
-using System;
 using System.Globalization;
-using System.Linq;
 using System.Transactions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0558_InternalOperationForcedExecutionOfDelayedQueriesWithoutPersist.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0558_InternalOperationForcedExecutionOfDelayedQueriesWithoutPersist.cs
index 0909ce6383..256b6d9d6d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0558_InternalOperationForcedExecutionOfDelayedQueriesWithoutPersist.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0558_InternalOperationForcedExecutionOfDelayedQueriesWithoutPersist.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.10.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Text;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0563_IncorrectPersistActionSequence.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0563_IncorrectPersistActionSequence.cs
index c2e24193b1..5e63746d3c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0563_IncorrectPersistActionSequence.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0563_IncorrectPersistActionSequence.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.10.27
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Validation;
 using model1 = Xtensive.Orm.Tests.Issues.IssueJira0563_IncorrectPersistActionSequenceModel1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0566_IndexOnRemovableEntityBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0566_IndexOnRemovableEntityBug.cs
index 979ef4cdae..9bf9cbc054 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0566_IndexOnRemovableEntityBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0566_IndexOnRemovableEntityBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.11.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0570_InOperationDoesNotCreateTemporaryTable.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0570_InOperationDoesNotCreateTemporaryTable.cs
index 79e6285b5d..fc56216421 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0570_InOperationDoesNotCreateTemporaryTable.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0570_InOperationDoesNotCreateTemporaryTable.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.08.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Runtime.InteropServices;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0571_MySqlKeyGenerationProblem.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0571_MySqlKeyGenerationProblem.cs
index d47e4099e4..85e96334f7 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0571_MySqlKeyGenerationProblem.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0571_MySqlKeyGenerationProblem.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.02.03
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0573_IncorrectMappingOfStructureFields.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0573_IncorrectMappingOfStructureFields.cs
index 8baef84059..8f4bf3117e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0573_IncorrectMappingOfStructureFields.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0573_IncorrectMappingOfStructureFields.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.02.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0573_IncorrectMappingOfStructureFieldsModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0577_EntityChangesRegistryIsNotEmptyAfterPersistFailed.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0577_EntityChangesRegistryIsNotEmptyAfterPersistFailed.cs
index 484a7b5142..528ea875e5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0577_EntityChangesRegistryIsNotEmptyAfterPersistFailed.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0577_EntityChangesRegistryIsNotEmptyAfterPersistFailed.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.03.18
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0584_IncorrectMappingOfColumnInQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0584_IncorrectMappingOfColumnInQuery.cs
index b91c96a2ad..cc0a09f9aa 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0584_IncorrectMappingOfColumnInQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0584_IncorrectMappingOfColumnInQuery.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.05.21
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0586_AnonymousTypeComparisonBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0586_AnonymousTypeComparisonBug.cs
index 7783e28a32..1da0679a9b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0586_AnonymousTypeComparisonBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0586_AnonymousTypeComparisonBug.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.05.28
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0586_AnonymousTypeComparisonBugModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0587_KeyComparisonBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0587_KeyComparisonBug.cs
index a5cb9251f7..fe6ab6df03 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0587_KeyComparisonBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0587_KeyComparisonBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.06.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0593_AggregateForSingleColumnTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0593_AggregateForSingleColumnTest.cs
index 4a194139c4..25e4fe55a2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0593_AggregateForSingleColumnTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0593_AggregateForSingleColumnTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.09.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0604_SetOperationsWithDuplicateFieldsUsageFail.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0604_SetOperationsWithDuplicateFieldsUsageFail.cs
index e2f5142e97..defded21ba 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0604_SetOperationsWithDuplicateFieldsUsageFail.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0604_SetOperationsWithDuplicateFieldsUsageFail.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2015.09.14
 
-using System;
 using System.Globalization;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0607_ColumnUselessRecreationsTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0607_ColumnUselessRecreationsTest.cs
index adf32fed02..df01919650 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0607_ColumnUselessRecreationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0607_ColumnUselessRecreationsTest.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Modelling.Actions;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0609_RewritingQueriesInClosure.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0609_RewritingQueriesInClosure.cs
index d5ebc848d2..9e27d67c1d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0609_RewritingQueriesInClosure.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0609_RewritingQueriesInClosure.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2009.11.02
 
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0612_NonPairedReferencesSearchBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0612_NonPairedReferencesSearchBug.cs
index 4802275a8f..cd9bfaa0a5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0612_NonPairedReferencesSearchBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0612_NonPairedReferencesSearchBug.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0612_ReferenceFinderBugModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0613_DataCleanUpInPerformSafely.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0613_DataCleanUpInPerformSafely.cs
index 3b451f3fad..e6a1c03aeb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0613_DataCleanUpInPerformSafely.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0613_DataCleanUpInPerformSafely.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.04.27
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Model;
 using userCase = Xtensive.Orm.Tests.Issues.IssueJira0613_DataCleanUpInPerformSafelyModel.UserCase;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0614_TypeMappingCachingInMaterializationContext.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0614_TypeMappingCachingInMaterializationContext.cs
index f9b80f8cc0..d6df3e0d30 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0614_TypeMappingCachingInMaterializationContext.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0614_TypeMappingCachingInMaterializationContext.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Diagnostics;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0616_ExistanceProviderProcessingBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0616_ExistanceProviderProcessingBug.cs
index 22d6e25d44..be0c5ad8db 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0616_ExistanceProviderProcessingBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0616_ExistanceProviderProcessingBug.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.12.04
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0617_IncorrectRemoveOfRedundantColumns.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0617_IncorrectRemoveOfRedundantColumns.cs
index 01c2df046e..8c3f54d0cb 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0617_IncorrectRemoveOfRedundantColumns.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0617_IncorrectRemoveOfRedundantColumns.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.12.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Dynamic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0619_InvalidExpressionInOrderBy.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0619_InvalidExpressionInOrderBy.cs
index 09f6ee784c..7447f4d6d8 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0619_InvalidExpressionInOrderBy.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0619_InvalidExpressionInOrderBy.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.12.08
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_FieldInitializationTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_FieldInitializationTest.cs
index ac5ad2d4a5..0dec13f61a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_FieldInitializationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_FieldInitializationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.05.03
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_PocoClassPropertyRenitialization.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_PocoClassPropertyRenitialization.cs
index bd6ddbc37a..19bcd539f6 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_PocoClassPropertyRenitialization.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0627_PocoClassPropertyRenitialization.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.12.31
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0630_IncorrectColumnOrderOfPKIndexOfInterfaceTypes.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0630_IncorrectColumnOrderOfPKIndexOfInterfaceTypes.cs
index 09cdeeed96..e70c0c92f5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0630_IncorrectColumnOrderOfPKIndexOfInterfaceTypes.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0630_IncorrectColumnOrderOfPKIndexOfInterfaceTypes.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2016.03.31
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0630_IncorrectColumnOrderOfPKIndexOfInterfaceTypesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0636_SessionCacheTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0636_SessionCacheTest.cs
index 17f367fd34..6d12bb4bd2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0636_SessionCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0636_SessionCacheTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.05.16
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0637_EntitySetFullOfNullsOnEnumeration.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0637_EntitySetFullOfNullsOnEnumeration.cs
index 36c3071f76..daa6f78ce5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0637_EntitySetFullOfNullsOnEnumeration.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0637_EntitySetFullOfNullsOnEnumeration.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.07.26
 
-using System.Linq;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0637_EntitySetFullOfNullsOnEnumerationModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0641_IndexFilterExpressionTranslationBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0641_IndexFilterExpressionTranslationBug.cs
index 542edeca8e..361a3e68b4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0641_IndexFilterExpressionTranslationBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0641_IndexFilterExpressionTranslationBug.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.08.09
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0643_OracleDateTimeOffsetExtractionBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0643_OracleDateTimeOffsetExtractionBug.cs
index 853403c9f5..4457fd7b5d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0643_OracleDateTimeOffsetExtractionBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0643_OracleDateTimeOffsetExtractionBug.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.04.29
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0647_StoredDomainModelMappingsUpdateBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0647_StoredDomainModelMappingsUpdateBug.cs
index 80259559ab..3c38d722d5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0647_StoredDomainModelMappingsUpdateBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0647_StoredDomainModelMappingsUpdateBug.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.04.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0656_RemapRestoresRemovedReferences.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0656_RemapRestoresRemovedReferences.cs
index f398eedf72..3c113e5c9c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0656_RemapRestoresRemovedReferences.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0656_RemapRestoresRemovedReferences.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using System.Runtime;
 using System.Runtime.InteropServices;
 using JetBrains.Annotations;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0659_EnumExpressionsAndConstantsTranslationBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0659_EnumExpressionsAndConstantsTranslationBug.cs
index b5020a635b..54afb4aa87 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0659_EnumExpressionsAndConstantsTranslationBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0659_EnumExpressionsAndConstantsTranslationBug.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.08.08
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0659_GroupByConditionalExpressionWithEnumsModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0674_ReferenceFinderBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0674_ReferenceFinderBug.cs
index 8454221f49..3b121485d5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0674_ReferenceFinderBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0674_ReferenceFinderBug.cs
@@ -1,4 +1,3 @@
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0674_ReferenceFinderBugModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0675_EntityChangeRegistryDoesntClear.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0675_EntityChangeRegistryDoesntClear.cs
index 0daac39dee..6d5c20a46d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0675_EntityChangeRegistryDoesntClear.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0675_EntityChangeRegistryDoesntClear.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Reflection;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Interfaces.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0702_QueryingWithoutOpenedTransaction.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0702_QueryingWithoutOpenedTransaction.cs
index e9ee34ada0..792f63766d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0702_QueryingWithoutOpenedTransaction.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0702_QueryingWithoutOpenedTransaction.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0708_StackOverflowOnDifferetialTupleMerge.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0708_StackOverflowOnDifferetialTupleMerge.cs
index db5574b7cc..ce37b6469d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0708_StackOverflowOnDifferetialTupleMerge.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0708_StackOverflowOnDifferetialTupleMerge.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2017.09.06
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0708_StackOverflowOnDifferetialTupleMergeModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0710_IndirectStructureChildFKAbsence.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0710_IndirectStructureChildFKAbsence.cs
index 6012ea752f..bb23845fb7 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0710_IndirectStructureChildFKAbsence.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0710_IndirectStructureChildFKAbsence.cs
@@ -4,8 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2017.09.01
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0712_IncorrectDefaultEnumValueTranslation.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0712_IncorrectDefaultEnumValueTranslation.cs
index 2ca1bfc24b..6068a3d369 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0712_IncorrectDefaultEnumValueTranslation.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0712_IncorrectDefaultEnumValueTranslation.cs
@@ -4,7 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2017.09.15
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0718_EntitySetEnumerationBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0718_EntitySetEnumerationBug.cs
index 48f0c8c8cf..a36c2fcd85 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0718_EntitySetEnumerationBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0718_EntitySetEnumerationBug.cs
@@ -4,9 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2017.12.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0723_ContainsOverLocalCollectionError.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0723_ContainsOverLocalCollectionError.cs
index f853453bd7..cefd6a6992 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0723_ContainsOverLocalCollectionError.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0723_ContainsOverLocalCollectionError.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2018.01.31
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0723_IncludeFilterMappingGathererHandlesMemberExpressionBadlyModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0728_NullGroupHasNoElementsTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0728_NullGroupHasNoElementsTest.cs
index 10b0bfb016..44a825bc1b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0728_NullGroupHasNoElementsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0728_NullGroupHasNoElementsTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2018.05.08
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0735_WrongTypeIdsInValidateMode.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0735_WrongTypeIdsInValidateMode.cs
index f8ade435c8..efba74ee34 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0735_WrongTypeIdsInValidateMode.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0735_WrongTypeIdsInValidateMode.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.06.17
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using V1 = Xtensive.Orm.Tests.Issues.IssueJira0735_WrongTypeIdsInValidateModeModel.V1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0739_StructureFieldsRemapOnCastBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0739_StructureFieldsRemapOnCastBug.cs
index e06e751446..4fe0e38e2e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0739_StructureFieldsRemapOnCastBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0739_StructureFieldsRemapOnCastBug.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.12.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0740_EntitySetFieldsRemapOnCastBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0740_EntitySetFieldsRemapOnCastBug.cs
index 6154bdc58e..92557cba0f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0740_EntitySetFieldsRemapOnCastBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0740_EntitySetFieldsRemapOnCastBug.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.12.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0742_QueryPreprocessorClosureExpressionSupport.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0742_QueryPreprocessorClosureExpressionSupport.cs
index 55a1a464c8..ae963fca84 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0742_QueryPreprocessorClosureExpressionSupport.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0742_QueryPreprocessorClosureExpressionSupport.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using NUnit.Framework.Constraints;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0743_IncludeDoesNotWorkWithSubqueries.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0743_IncludeDoesNotWorkWithSubqueries.cs
index aa53998fcb..ae48fcda2d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0743_IncludeDoesNotWorkWithSubqueries.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0743_IncludeDoesNotWorkWithSubqueries.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.10.18
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0746_LikeBehaviorDifferentOnClientSide.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0746_LikeBehaviorDifferentOnClientSide.cs
index 8c725e7e6e..182da4173c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0746_LikeBehaviorDifferentOnClientSide.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0746_LikeBehaviorDifferentOnClientSide.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.25.10
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0752_RecycledAttributeDontWorkForPersistentGenericInterface.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0752_RecycledAttributeDontWorkForPersistentGenericInterface.cs
index b03259fcc7..de797e9d6b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0752_RecycledAttributeDontWorkForPersistentGenericInterface.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0752_RecycledAttributeDontWorkForPersistentGenericInterface.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.12.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Modelling.Actions;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0759_UnableToTranslateOfTypeSelectExpression.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0759_UnableToTranslateOfTypeSelectExpression.cs
index a32015ea29..0e8da042c3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0759_UnableToTranslateOfTypeSelectExpression.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0759_UnableToTranslateOfTypeSelectExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2019.01.31
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0759_UnableToTranslateOfTypeSelectExpressionModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0760_OverrideFieldNameAttributeRuinsFieldMappingOnUpgrade.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0760_OverrideFieldNameAttributeRuinsFieldMappingOnUpgrade.cs
index 34ad9daf64..a92434525d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0760_OverrideFieldNameAttributeRuinsFieldMappingOnUpgrade.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0760_OverrideFieldNameAttributeRuinsFieldMappingOnUpgrade.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0761_ReadingAverageByDecimalField.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0761_ReadingAverageByDecimalField.cs
index dd373eb00c..d3776f4c4f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0761_ReadingAverageByDecimalField.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0761_ReadingAverageByDecimalField.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2019.02.14
 
-using System;
 using System.Data.SqlTypes;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0761_ReadingAverageByDecimalFieldModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0767_OfTypeForNonGenericSources.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0767_OfTypeForNonGenericSources.cs
index 162f18cf77..595775c903 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0767_OfTypeForNonGenericSources.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0767_OfTypeForNonGenericSources.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.06.21
 
-using System.Linq;
 using System.Runtime.Serialization;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0768_NullableFieldsBecomeNonNullable.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0768_NullableFieldsBecomeNonNullable.cs
index 28ee8246e4..105b56c03f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0768_NullableFieldsBecomeNonNullable.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0768_NullableFieldsBecomeNonNullable.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.07.17
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0768_NullableFieldsBecomeNonNullableModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0778_PrefetchStackOverflow.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0778_PrefetchStackOverflow.cs
index e602bfc127..3b48fbd2a5 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0778_PrefetchStackOverflow.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0778_PrefetchStackOverflow.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.10.24
 
-using System;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0779_SetOperationsWithOrderAndTakeWrongQuery.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0779_SetOperationsWithOrderAndTakeWrongQuery.cs
index 70a06c55cb..dc0383bda3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0779_SetOperationsWithOrderAndTakeWrongQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0779_SetOperationsWithOrderAndTakeWrongQuery.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.10.25
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0781_CompositeKeyReferencesRemapOnCast.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0781_CompositeKeyReferencesRemapOnCast.cs
index 03dc7c69a2..f469e70c55 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0781_CompositeKeyReferencesRemapOnCast.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0781_CompositeKeyReferencesRemapOnCast.cs
@@ -5,9 +5,6 @@
 // Created:    2019.12.16
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0782_StorageSequenctialGeneratorBug.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0782_StorageSequenctialGeneratorBug.cs
index 979e5c9fdb..95beb2732e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0782_StorageSequenctialGeneratorBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0782_StorageSequenctialGeneratorBug.cs
@@ -5,9 +5,6 @@
 // Created:    2019.12.16
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0784_IncludedTypeIdReferenceBreaksTypedIndexCompilation.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0784_IncludedTypeIdReferenceBreaksTypedIndexCompilation.cs
index 33ae051598..d937dd3155 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0784_IncludedTypeIdReferenceBreaksTypedIndexCompilation.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0784_IncludedTypeIdReferenceBreaksTypedIndexCompilation.cs
@@ -5,9 +5,6 @@
 // Created:    2019.12.24
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AggregatesProblemTestBase.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AggregatesProblemTestBase.cs
index b3781aba09..4843598333 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AggregatesProblemTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AggregatesProblemTestBase.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.03.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AverageProcessingTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AverageProcessingTest.cs
index 0bde414aef..4f1d274415 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AverageProcessingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/AverageProcessingTest.cs
@@ -5,9 +5,6 @@
 // Created:    2020.03.26
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MaxProcessingTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MaxProcessingTest.cs
index 548b1a4751..b158c8e6f1 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MaxProcessingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MaxProcessingTest.cs
@@ -5,9 +5,6 @@
 // Created:    2020.03.26
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MinProcessingTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MinProcessingTest.cs
index 98d603d3d8..74f7723182 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MinProcessingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/MinProcessingTest.cs
@@ -5,9 +5,6 @@
 // Created:    2020.03.26
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/Model.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/Model.cs
index d07802dad2..6c3f68a0c3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/Model.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.03.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.Issues.IssueJira0786_SqlServerAggregatesProblem
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/SumProcessingTest.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/SumProcessingTest.cs
index 0b49326568..7548aa8b8e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/SumProcessingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0786_SqlServerAggregatesProblem/SumProcessingTest.cs
@@ -5,9 +5,6 @@
 // Created:    2020.03.26
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0792_UnableToRemoveAssignedEntityWithNonNullableAssociationField.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0792_UnableToRemoveAssignedEntityWithNonNullableAssociationField.cs
index 121ee94a07..bc3fa55989 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0792_UnableToRemoveAssignedEntityWithNonNullableAssociationField.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0792_UnableToRemoveAssignedEntityWithNonNullableAssociationField.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.02.14
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0793_FieldValidationTriggersLazyLoadFieldsFetch.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0793_FieldValidationTriggersLazyLoadFieldsFetch.cs
index 50a49ff183..d5e0c256ec 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0793_FieldValidationTriggersLazyLoadFieldsFetch.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0793_FieldValidationTriggersLazyLoadFieldsFetch.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.02.18
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Validation;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0795_EntitySetPrefetchDoesNotWork.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0795_EntitySetPrefetchDoesNotWork.cs
index f9ed87b2ec..3d2388b072 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0795_EntitySetPrefetchDoesNotWork.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0795_EntitySetPrefetchDoesNotWork.cs
@@ -5,9 +5,6 @@
 // Created:    2020.02.19
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Text;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0796_IgnoreHintPathGetsInvalid.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0796_IgnoreHintPathGetsInvalid.cs
index 7397ea19cc..84753e3f83 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0796_IgnoreHintPathGetsInvalid.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0796_IgnoreHintPathGetsInvalid.cs
@@ -5,9 +5,6 @@
 // Created:    2020.03.04
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Text;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0800_DtoInterfaceFieldInitializationWithinCtor.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0800_DtoInterfaceFieldInitializationWithinCtor.cs
index bf8f6e46e8..d96de2f381 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0800_DtoInterfaceFieldInitializationWithinCtor.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0800_DtoInterfaceFieldInitializationWithinCtor.cs
@@ -3,8 +3,6 @@
 // See the License.txt file in the project root for more information.
 
 using NUnit.Framework;
-using System;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0801_ReduntandColumnRemoverRemovesPartOfTempTableColumns.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0801_ReduntandColumnRemoverRemovesPartOfTempTableColumns.cs
index 252612b43e..84e896cf12 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira0801_ReduntandColumnRemoverRemovesPartOfTempTableColumns.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira0801_ReduntandColumnRemoverRemovesPartOfTempTableColumns.cs
@@ -5,9 +5,6 @@
 // Created:    2020.11.16
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.IssueJira0801_ReduntandColumnRemoverRemovesPartOfTempTableColumnsModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Issues/IssueJira_0530_LowSpeedDecimalMaterializationCouseSqlDecimalInternalException.cs b/Orm/Xtensive.Orm.Tests/Issues/IssueJira_0530_LowSpeedDecimalMaterializationCouseSqlDecimalInternalException.cs
index 70966d4fa4..6b945b6dc2 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/IssueJira_0530_LowSpeedDecimalMaterializationCouseSqlDecimalInternalException.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/IssueJira_0530_LowSpeedDecimalMaterializationCouseSqlDecimalInternalException.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2015.04.22
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion1.cs
index de6ee6880a..d22f5891e3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0694_SchemaUpgradeBug.Model.Version1
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion2.cs
index 3e34a4c892..c317471c9d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0694_SchemaUpgradeBug.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion3.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion3.cs
index c50971dff8..d7af6d4f97 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion3.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/ModelVersion3.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0694_SchemaUpgradeBug.Model.Version3
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/UpgradeTest.cs
index fe5f16dd32..ca285be864 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.Issues.Issue_0694_SchemaUpgradeBug.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/Upgrader.cs
index 0abc973b19..dda57819e0 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0694_SchemaUpgradeBug/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
 using M1 = Xtensive.Orm.Tests.Issues.Issue_0694_SchemaUpgradeBug.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion1.cs
index 6a1eb455c8..e76276398e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0716_UpgradeFailsInValidateMode.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion2.cs
index 94714c87f6..f73abf6832 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0716_UpgradeFailsInValidateMode.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/UpgradeTest.cs
index 9617dc9bb2..2271ec9a12 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.Issues.Issue_0716_UpgradeFailsInValidateMode.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/Upgrader.cs
index a5bf9d3453..811bf90faf 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0716_UpgradeFailsInValidateMode/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
 using M1 = Xtensive.Orm.Tests.Issues.Issue_0716_UpgradeFailsInValidateMode.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion1.cs
index 89eaee2b10..b2a27f05a3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0743_UpgradeToNonNullableTypes.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion2.cs
index be285df7d3..492613cf9d 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0743_UpgradeToNonNullableTypes.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/UpgradeTest.cs
index e49bd97200..359ee201ae 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/Upgrader.cs
index 71f9e4b784..e00515b123 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0743_UpgradeToNonNullableTypes/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Tests.Issues.Issue_0743_UpgradeToNonNullableTypes.Model.Version2;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion1.cs
index d6f230fc3a..7fa01394c4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0769_ByteArrayColumnUpgrade.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion2.cs
index f4f16e36dc..9cef5f70da 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0769_ByteArrayColumnUpgrade.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/UpgradeTest.cs
index 08916f1eb6..e059ee5b89 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/UpgradeTest.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/Upgrader.cs
index fbffb7a818..7fb791ce00 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0769_ByteArrayColumnUpgrade/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion1.cs
index bcf8fa0983..159461a139 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0834_HintGeneratorBug.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion2.cs
index 19b31c2966..c89c413db3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/ModelVersion2.cs
@@ -6,7 +6,6 @@
 
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0834_HintGeneratorBug.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/UpgradeTest.cs
index 86559abb3a..c5b953f20f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using M1 = Xtensive.Orm.Tests.Issues.Issue_0834_HintGeneratorBug.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/Upgrader.cs
index 2624531860..0ba5a9f496 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0837_HintGeneratorBug/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion1.cs
index 2cb4499a3f..1e95f9b01c 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion2.cs
index 56d074b956..c951209605 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/ModelVersion2.cs
@@ -6,7 +6,6 @@
 
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/UpgradeTest.cs
index a3666f0afd..731140a5b0 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using M1 = Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/Upgrader.cs
index 82900cabe0..e3805ce041 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion1.cs
index fb1393a3b6..3d3586bf06 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug2.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion2.cs
index 59ad5f4616..a7a3d915a4 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/ModelVersion2.cs
@@ -6,7 +6,6 @@
 
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug2.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/UpgradeTest.cs
index 56fc14be32..1b94aabf80 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/Upgrader.cs
index aa1333bca9..d55397a82b 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug2/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Modelling.Comparison.Hints;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion1.cs
index ae780f4a1e..50753983c9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug3.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion2.cs
index cba26771df..83fa3771d3 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/ModelVersion2.cs
@@ -6,7 +6,6 @@
 
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug3.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/UpgradeTest.cs
index 8331744350..152afa92d8 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using M1 = Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug3.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/Upgrader.cs
index e5398d208f..2854783f5e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug3/Upgrader.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
 using Microsoft.Data.SqlClient;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Services;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion1.cs
index f18d4f0e4d..389e0cfa03 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug4.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion2.cs
index ef9e530c50..f953d1bc0f 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/ModelVersion2.cs
@@ -6,7 +6,6 @@
 
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug4.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/UpgradeTest.cs
index bd386e596e..a43431f734 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using M1 = Xtensive.Orm.Tests.Issues.Issue_0841_HintGeneratorBug4.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/Upgrader.cs
index a57aada164..0b0792db76 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_0841_HintGeneratorBug4/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/Issue_OfTypeMissesImplementors.cs b/Orm/Xtensive.Orm.Tests/Issues/Issue_OfTypeMissesImplementors.cs
index 5bd8fff4a3..ed4e793588 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/Issue_OfTypeMissesImplementors.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/Issue_OfTypeMissesImplementors.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.08.21
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.Issue_OfTypeMissesImplementors_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/KeyFormatBug.cs b/Orm/Xtensive.Orm.Tests/Issues/KeyFormatBug.cs
index 448bdad2f9..8f3b5b75b9 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/KeyFormatBug.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/KeyFormatBug.cs
@@ -4,13 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.11
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues.KeyFormatBug
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/LocalCollectionsTest.cs b/Orm/Xtensive.Orm.Tests/Issues/LocalCollectionsTest.cs
index a574454355..7c468d1e3e 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/LocalCollectionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/LocalCollectionsTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.07.10
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.LocalCollectionsTest_Model;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/MaterializationMethodTest.cs b/Orm/Xtensive.Orm.Tests/Issues/MaterializationMethodTest.cs
index 7795fd4fc9..32a45f6852 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/MaterializationMethodTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/MaterializationMethodTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.MaterializationMethodTestsModel;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/NotEqualsForNullableColumnTest.cs b/Orm/Xtensive.Orm.Tests/Issues/NotEqualsForNullableColumnTest.cs
index 2ed47c4c70..2a87c40204 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/NotEqualsForNullableColumnTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/NotEqualsForNullableColumnTest.cs
@@ -4,12 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2011.03.25
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Issues.NotEqualsForNullableColumnTest_Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Issues
 {
diff --git a/Orm/Xtensive.Orm.Tests/Issues/StrangeLockingExceptionTest.cs b/Orm/Xtensive.Orm.Tests/Issues/StrangeLockingExceptionTest.cs
index 061c76a767..e59abc5c0a 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/StrangeLockingExceptionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/StrangeLockingExceptionTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.20
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Issues/StructureFieldRemoveTest.cs b/Orm/Xtensive.Orm.Tests/Issues/StructureFieldRemoveTest.cs
index 7ab716e2e7..ab6b208979 100644
--- a/Orm/Xtensive.Orm.Tests/Issues/StructureFieldRemoveTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Issues/StructureFieldRemoveTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 using V1 = Xtensive.Orm.Tests.Issues.StructureFieldRemoveModel1;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/AggregateTest.cs b/Orm/Xtensive.Orm.Tests/Linq/AggregateTest.cs
index da0c85d497..18302e6f29 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/AggregateTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/AggregateTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.04
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ArrayTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ArrayTest.cs
index 12d4adbd59..fcc6bf8307 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ArrayTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ArrayTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.04.30
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Comparison;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/CompiledQueriesWithClosureTest.cs b/Orm/Xtensive.Orm.Tests/Linq/CompiledQueriesWithClosureTest.cs
index 3e00d77922..6b18251047 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/CompiledQueriesWithClosureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/CompiledQueriesWithClosureTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.16
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using CompiledQueriesWithClosureTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ComplexTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ComplexTest.cs
index c6facb1178..205bc303dc 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ComplexTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ComplexTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.25
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ConditionalTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ConditionalTest.cs
index 83af18ca46..cb60d3ae0c 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ConditionalTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ConditionalTest.cs
@@ -4,12 +4,10 @@
 // Created by: Alexey Gamzov
 // Created:    2009.04.21
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.ConditionalTestModel;
 using Xtensive.Orm.Tests.Storage.ForeignKeys;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Linq.ConditionalTestModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ContainsAnyAllTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ContainsAnyAllTest.cs
index acfe07085f..c059a1ce32 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ContainsAnyAllTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ContainsAnyAllTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ContainsOverKeysCollectionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ContainsOverKeysCollectionTest.cs
index c330d881f0..09ca9c44d5 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ContainsOverKeysCollectionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ContainsOverKeysCollectionTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2013.12.30
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.ContainsOverKeysCollectionTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ContainsTableTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ContainsTableTest.cs
index 08f4566b83..b6deaac3ab 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ContainsTableTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ContainsTableTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.09
 
-using System;
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ConvariantQueriesTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ConvariantQueriesTest.cs
index 33015db847..1d0dc7e664 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ConvariantQueriesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ConvariantQueriesTest.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.02
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/CustomExpressionCompilers.cs b/Orm/Xtensive.Orm.Tests/Linq/CustomExpressionCompilers.cs
index d23f5a5ea4..84a5944f6b 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/CustomExpressionCompilers.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/CustomExpressionCompilers.cs
@@ -4,14 +4,12 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.13
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.CustomExpressionCompilersModel;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Linq.CustomExpressionCompilersModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DataContextTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DataContextTest.cs
index d4e4b42963..4984a80d9c 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DataContextTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DataContextTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.02
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/BaseTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/BaseTest.cs
index dbb8671b46..00414f8a97 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/BaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/BaseTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.09.15
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/ConstructorTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/ConstructorTest.cs
index 13c5eb95af..2de2a4ce72 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/ConstructorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/ConstructorTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/DistinctTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/DistinctTest.cs
index e08861fb73..eacd63c01a 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/DistinctTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/DistinctTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/GroupByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/GroupByTest.cs
index 1d3d5389fb..90fe5a06b2 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/GroupByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/GroupByTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/JoinTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/JoinTest.cs
index 4c286e96d5..95804a6da2 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/JoinTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/JoinTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/MinMaxTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/MinMaxTest.cs
index 215eec2de6..d8b6b97f9d 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/MinMaxTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/MinMaxTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OperationsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OperationsTest.cs
index cb732ef832..b07ca88feb 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OperationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OperationsTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OrderByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OrderByTest.cs
index 857fffdbb8..9cc9f4b484 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OrderByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/OrderByTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/PartsExtractionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/PartsExtractionTest.cs
index 5703e2a9b9..affabf702c 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/PartsExtractionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/PartsExtractionTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/WhereTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/WhereTest.cs
index a235d85231..3825697c1a 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/WhereTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateOnly/WhereTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/ConstructorTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/ConstructorTest.cs
index 693037f7c0..7978066f60 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/ConstructorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/ConstructorTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/DistinctTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/DistinctTest.cs
index b4e4e6607e..b6afd4dec3 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/DistinctTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/DistinctTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/GroupByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/GroupByTest.cs
index b55afd4ba1..c21004fd06 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/GroupByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/GroupByTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/JoinTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/JoinTest.cs
index 0c0b34bfac..cbfb4a4850 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/JoinTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/JoinTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/MinMaxTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/MinMaxTest.cs
index f00d2194b2..a1da9332b3 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/MinMaxTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/MinMaxTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/OrderByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/OrderByTest.cs
index ece14ffa9c..acb3a58420 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/OrderByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/OrderByTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/PartsExtractionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/PartsExtractionTest.cs
index 1d1b2a574e..f13e588936 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/PartsExtractionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/PartsExtractionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/WhereTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/WhereTest.cs
index 596b0cb879..8b0cc8a87e 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/WhereTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTime/WhereTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeBaseTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeBaseTest.cs
index 85b19ff1af..6d7e85eff3 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeBaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeBaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.09.15
 
-using System;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/ComparisonTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/ComparisonTest.cs
index fd891d73e8..2facbc42b3 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/ComparisonTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/ComparisonTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DateTimeOffsetConstructorTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DateTimeOffsetConstructorTest.cs
index a0dd39a0a2..70bcf76ab2 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DateTimeOffsetConstructorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DateTimeOffsetConstructorTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.09.09
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DistinctTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DistinctTest.cs
index 45930a07fc..25a463b6cd 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DistinctTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/DistinctTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/GroupByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/GroupByTest.cs
index 943dc2c011..0a1437b859 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/GroupByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/GroupByTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/JoinTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/JoinTest.cs
index 3aeddb5121..ea88f24bb2 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/JoinTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/JoinTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/MinMaxTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/MinMaxTest.cs
index 2c5e16b793..e3dc51d3ff 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/MinMaxTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/MinMaxTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.07.29
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OperationsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OperationsTest.cs
index f02738374b..bcc9b5757b 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OperationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OperationsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OrderByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OrderByTest.cs
index 079a6e1d2d..3901c083fe 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OrderByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/OrderByTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.07.29
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/PartsExtractionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/PartsExtractionTest.cs
index 05d5b32396..24534344a5 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/PartsExtractionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/PartsExtractionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/WhereTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/WhereTest.cs
index 5c73276e5d..6b30644e89 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/WhereTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/WhereTest.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffsetBaseTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffsetBaseTest.cs
index cd454cfa24..c0d95a6370 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffsetBaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffsetBaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.09.15
 
-using System;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/JoinResult{T}.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/JoinResult{T}.cs
index c7034b49c8..7f0bf7364d 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/JoinResult{T}.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/JoinResult{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
 
 namespace Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/Model.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/Model.cs
index cd6c8a03dc..cadfd5966b 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.01
 
-using System;
 
 namespace Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ComparisonTestTimeOnly.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ComparisonTestTimeOnly.cs
index a36e8382f5..476575c84d 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ComparisonTestTimeOnly.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ComparisonTestTimeOnly.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ConstructorTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ConstructorTest.cs
index 43760c611f..d1d53f63e2 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ConstructorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/ConstructorTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/DistinctTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/DistinctTest.cs
index e40a4330d2..c15e8503cc 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/DistinctTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/DistinctTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/GroupByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/GroupByTest.cs
index ae1986d5aa..a32198a422 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/GroupByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/GroupByTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/JoinTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/JoinTest.cs
index a71c13f94b..7e8f53dab6 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/JoinTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/JoinTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/MinMaxTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/MinMaxTest.cs
index a7b694b884..68abb3f444 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/MinMaxTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/MinMaxTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OperationsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OperationsTest.cs
index 0da689b0ff..0f41016949 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OperationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OperationsTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OrderByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OrderByTest.cs
index 8305ca83bb..98ddaee9ea 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OrderByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/OrderByTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/PartsExtractionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/PartsExtractionTest.cs
index d6e67fd160..c235a63a9f 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/PartsExtractionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/PartsExtractionTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/TimeOnlyToString.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/TimeOnlyToString.cs
index 90c34f6293..f53f810957 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/TimeOnlyToString.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/TimeOnlyToString.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/WhereTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/WhereTest.cs
index 486f3e12fc..6545e13970 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/WhereTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/TimeOnly/WhereTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.DateTimeAndDateTimeOffset.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DistinctTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DistinctTest.cs
index 822acb7ef4..1dcc9d8435 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DistinctTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DistinctTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.04
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DoubleAggregateToStructTest.cs b/Orm/Xtensive.Orm.Tests/Linq/DoubleAggregateToStructTest.cs
index 165b463657..1f105eb26f 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DoubleAggregateToStructTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DoubleAggregateToStructTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.26
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.DoubleAggregateToStructTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/DynamicallyDefinedFields.cs b/Orm/Xtensive.Orm.Tests/Linq/DynamicallyDefinedFields.cs
index d49ac15dc6..44031352de 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/DynamicallyDefinedFields.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/DynamicallyDefinedFields.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.06.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/EntitySetTest.cs b/Orm/Xtensive.Orm.Tests/Linq/EntitySetTest.cs
index 99e4a5c39c..4a6f959287 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/EntitySetTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/EntitySetTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ExecuteTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ExecuteTest.cs
index 31a791da1a..edbff8ab0f 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ExecuteTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ExecuteTest.cs
@@ -5,7 +5,6 @@
 // Created:    2009.12.15
 
 using System.Collections;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/FirstSingleTest.cs b/Orm/Xtensive.Orm.Tests/Linq/FirstSingleTest.cs
index 121b007fcc..0c2c3095ab 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/FirstSingleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/FirstSingleTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.04
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/FreeTextTest.cs b/Orm/Xtensive.Orm.Tests/Linq/FreeTextTest.cs
index ddeb0932b3..0896356580 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/FreeTextTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/FreeTextTest.cs
@@ -4,14 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.14
 
-using System;
-using System.Collections.Generic;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Linq
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/FullTextColumnsDeclarationTest.cs b/Orm/Xtensive.Orm.Tests/Linq/FullTextColumnsDeclarationTest.cs
index 0bc5c38bcb..a7f1547146 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/FullTextColumnsDeclarationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/FullTextColumnsDeclarationTest.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/GroupByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/GroupByTest.cs
index 11e11d087a..d1e9b533b4 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/GroupByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/GroupByTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Tuples;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/GroupByTwoEntitiesWithSameColumnsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/GroupByTwoEntitiesWithSameColumnsTest.cs
index bb85d08466..b542fc4386 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/GroupByTwoEntitiesWithSameColumnsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/GroupByTwoEntitiesWithSameColumnsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.06
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.GroupByTwoEntitiesWithSameColumnsTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/InOverSubtypeColumnTest.cs b/Orm/Xtensive.Orm.Tests/Linq/InOverSubtypeColumnTest.cs
index 1111011ffd..151ada8d82 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/InOverSubtypeColumnTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/InOverSubtypeColumnTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.07
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/InTest.cs b/Orm/Xtensive.Orm.Tests/Linq/InTest.cs
index 05a57056c1..ed01a4c4d9 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/InTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/InTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.09.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Rse;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/IndexedMethodsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/IndexedMethodsTest.cs
index 722c00dac7..ee2dc00bf5 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/IndexedMethodsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/IndexedMethodsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.14
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/Interfaces/AlphabetTest.cs b/Orm/Xtensive.Orm.Tests/Linq/Interfaces/AlphabetTest.cs
index a12eb9674f..4a294936aa 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/Interfaces/AlphabetTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/Interfaces/AlphabetTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SimpleTest.cs
index d0ee06a289..d1f3970767 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SimpleTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.01
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SlaveryTest.cs b/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SlaveryTest.cs
index 2bb690c5e5..c153803d4c 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SlaveryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/Interfaces/SlaveryTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.24
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.ObjectModel.Interfaces.Slavery;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/JoinTest.cs b/Orm/Xtensive.Orm.Tests/Linq/JoinTest.cs
index dd60c3db2d..19a4f53a10 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/JoinTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/JoinTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.12.17
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Comparison;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/KeysUnionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/KeysUnionTest.cs
index 8bcc89de75..508216a85a 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/KeysUnionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/KeysUnionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.11
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.KeysUnionTestModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsComplexTest.cs b/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsComplexTest.cs
index cbbf24ecbe..6f1cf88ff5 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsComplexTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsComplexTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2009.09.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.LocalCollectionsComplexTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsTest.cs
index 3e904820db..f3ff6cca63 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/LocalCollectionsTest.cs
@@ -4,17 +4,13 @@
 // Created by: Alexey Gamzov
 // Created:    2009.09.07
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Tests.Linq.LocalCollectionsTest_Model;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Linq.LocalCollectionsTest_Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/LockTest.cs b/Orm/Xtensive.Orm.Tests/Linq/LockTest.cs
index 2f5d980d0b..bfaa454097 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/LockTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/LockTest.cs
@@ -4,12 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.08.25
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.Classes.cs b/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.Classes.cs
index 66a1f83820..046a233052 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.Classes.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.Classes.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.10
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.cs b/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.cs
index 05fc91c3e7..715ae885e3 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/MemberCompilerProviderTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Linq.MemberCompilation;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/MiscTest.cs b/Orm/Xtensive.Orm.Tests/Linq/MiscTest.cs
index 3fc39fd5ba..1403731f82 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/MiscTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/MiscTest.cs
@@ -5,8 +5,6 @@
 // Created:    2009.12.02
 
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToEntitiesSamples.cs b/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToEntitiesSamples.cs
index 1b33be70a2..44676c5ec5 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToEntitiesSamples.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToEntitiesSamples.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToSqlSamples.cs b/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToSqlSamples.cs
index d29e94afcf..6127adfb7d 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToSqlSamples.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/MsSamples/LinqToSqlSamples.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/NestedCollectionsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/NestedCollectionsTest.cs
index 763e53feaf..e70bd83649 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/NestedCollectionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/NestedCollectionsTest.cs
@@ -5,7 +5,6 @@
 // Created:    2009.04.16
 
 using System.Collections;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/NullableEnumMaterializationTest.cs b/Orm/Xtensive.Orm.Tests/Linq/NullableEnumMaterializationTest.cs
index 92a799f91a..ed6c5ec806 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/NullableEnumMaterializationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/NullableEnumMaterializationTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.13
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Linq.NullableEnumQueryTestModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Linq/OfTypeTest.cs b/Orm/Xtensive.Orm.Tests/Linq/OfTypeTest.cs
index 992cb8f054..e8aca38fbb 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/OfTypeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/OfTypeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2019.01.31
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/OrderByTest.cs b/Orm/Xtensive.Orm.Tests/Linq/OrderByTest.cs
index ead835ac70..51a6bbeb4b 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/OrderByTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/OrderByTest.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.01.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/PocoProjectionWithSubqueryTest.cs b/Orm/Xtensive.Orm.Tests/Linq/PocoProjectionWithSubqueryTest.cs
index faa7994565..5caf9947ab 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/PocoProjectionWithSubqueryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/PocoProjectionWithSubqueryTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.13
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.PocoProjectionWithSubqueryTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/ProjectToDtoWithInheritanceTest.cs b/Orm/Xtensive.Orm.Tests/Linq/ProjectToDtoWithInheritanceTest.cs
index dd01a7dcf3..a829c74852 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/ProjectToDtoWithInheritanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/ProjectToDtoWithInheritanceTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.26
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.ProjectToDtoWithInheritanceTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/QueryDumper.cs b/Orm/Xtensive.Orm.Tests/Linq/QueryDumper.cs
index 999e2a97ff..7cd3569a74 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/QueryDumper.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/QueryDumper.cs
@@ -4,11 +4,8 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.27
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/QueryMethodTests.cs b/Orm/Xtensive.Orm.Tests/Linq/QueryMethodTests.cs
index a1ad7ff5af..82e3ddc197 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/QueryMethodTests.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/QueryMethodTests.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.15
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/QueryPreprocessorSortingTest.cs b/Orm/Xtensive.Orm.Tests/Linq/QueryPreprocessorSortingTest.cs
index ef69bcc654..b3ac664f41 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/QueryPreprocessorSortingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/QueryPreprocessorSortingTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.07.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/QueryRootOverriding.cs b/Orm/Xtensive.Orm.Tests/Linq/QueryRootOverriding.cs
index d70e8137da..4dab87c9b1 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/QueryRootOverriding.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/QueryRootOverriding.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.02
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/RefTest.cs b/Orm/Xtensive.Orm.Tests/Linq/RefTest.cs
index 05fc6c3b37..67f87b1449 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/RefTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/RefTest.cs
@@ -4,11 +4,9 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.16
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Linq
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SearchConditionNodeVisitorTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SearchConditionNodeVisitorTest.cs
index dee7a67d26..668ee81f0b 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SearchConditionNodeVisitorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SearchConditionNodeVisitorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SelectDtoTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SelectDtoTest.cs
index b4fa754263..c0d951c54c 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SelectDtoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SelectDtoTest.cs
@@ -4,14 +4,12 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.18
 
-using System;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.Linq.Dto;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Linq
 {
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SelectManyTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SelectManyTest.cs
index 381acae2a8..a71eb6dbe3 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SelectManyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SelectManyTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SelectTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SelectTest.cs
index 0c218e418d..6950798e96 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SelectTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SelectTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2009.01.12
 
-using System.Collections.Generic;
 using NUnit.Framework;
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SelectWithAccessToLocalCollectionTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SelectWithAccessToLocalCollectionTest.cs
index bca8a17f0d..abde316d8f 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SelectWithAccessToLocalCollectionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SelectWithAccessToLocalCollectionTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.SelectWithAccessToLocalCollectionTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SetOperationsTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SetOperationsTest.cs
index 2f78310d42..e55d747955 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SetOperationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SetOperationsTest.cs
@@ -4,8 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.06
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SkipTakeElementAtTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SkipTakeElementAtTest.cs
index e7746d1347..bb92b01aee 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SkipTakeElementAtTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SkipTakeElementAtTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SortExpressionExtractorTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SortExpressionExtractorTest.cs
index 366407f674..94eefbb615 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SortExpressionExtractorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SortExpressionExtractorTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SubqueryAndComputedColumnOptimizationTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SubqueryAndComputedColumnOptimizationTest.cs
index e9b4b65be2..ffbdd6a916 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SubqueryAndComputedColumnOptimizationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SubqueryAndComputedColumnOptimizationTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.08.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/SubqueryWithCalculatedFieldTest.cs b/Orm/Xtensive.Orm.Tests/Linq/SubqueryWithCalculatedFieldTest.cs
index 7a9d116f23..37758ed8b8 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/SubqueryWithCalculatedFieldTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/SubqueryWithCalculatedFieldTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.21
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/TagTest.cs b/Orm/Xtensive.Orm.Tests/Linq/TagTest.cs
index 54c80bd4ce..8dce8cee6e 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/TagTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/TagTest.cs
@@ -4,12 +4,8 @@
 // Created by: Edgar Isajanyan
 // Created:    2021.09.13
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/TypeAsOptimizationTest.cs b/Orm/Xtensive.Orm.Tests/Linq/TypeAsOptimizationTest.cs
index 4d21f217d3..770958b081 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/TypeAsOptimizationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/TypeAsOptimizationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.08.28
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.TypeAsOptimizationTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/TypeCastAndInheritanceTest.cs b/Orm/Xtensive.Orm.Tests/Linq/TypeCastAndInheritanceTest.cs
index 01bbbda30a..482523e24d 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/TypeCastAndInheritanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/TypeCastAndInheritanceTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.04.10
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/WhereByEnumTest.cs b/Orm/Xtensive.Orm.Tests/Linq/WhereByEnumTest.cs
index c2e6063f9f..f2b904d1a1 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/WhereByEnumTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/WhereByEnumTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Linq/WhereTest.cs b/Orm/Xtensive.Orm.Tests/Linq/WhereTest.cs
index fdf8e02e66..b221ef2ac6 100644
--- a/Orm/Xtensive.Orm.Tests/Linq/WhereTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Linq/WhereTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.12.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm.Tests/Model/AssociationTest.cs b/Orm/Xtensive.Orm.Tests/Model/AssociationTest.cs
index aa84b1f06c..ecca6a4da7 100644
--- a/Orm/Xtensive.Orm.Tests/Model/AssociationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/AssociationTest.cs
@@ -13,9 +13,6 @@
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.Association;
-using System.Linq;
-using System.Collections.Generic;
-using System;
 
 namespace Xtensive.Orm.Tests.Model.Association
 {
diff --git a/Orm/Xtensive.Orm.Tests/Model/AssociationsOverrideTest.cs b/Orm/Xtensive.Orm.Tests/Model/AssociationsOverrideTest.cs
index bd48612389..506cdcf8df 100644
--- a/Orm/Xtensive.Orm.Tests/Model/AssociationsOverrideTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/AssociationsOverrideTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.27
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.DiscardedAssociationsBugModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/AutoGenericsOverrideTest.cs b/Orm/Xtensive.Orm.Tests/Model/AutoGenericsOverrideTest.cs
index 5ed0fc28ae..b0895f1d8e 100644
--- a/Orm/Xtensive.Orm.Tests/Model/AutoGenericsOverrideTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/AutoGenericsOverrideTest.cs
@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Model/CycleReferenceTest.cs b/Orm/Xtensive.Orm.Tests/Model/CycleReferenceTest.cs
index d0a980061a..d7d1c6db7d 100644
--- a/Orm/Xtensive.Orm.Tests/Model/CycleReferenceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/CycleReferenceTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.04.16
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests/Model/CyclicContainedStructureTest.cs b/Orm/Xtensive.Orm.Tests/Model/CyclicContainedStructureTest.cs
index 033cc62f95..72ac440bbf 100644
--- a/Orm/Xtensive.Orm.Tests/Model/CyclicContainedStructureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/CyclicContainedStructureTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.06.16
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Model/CyclicHierarchyDependenciesTest.cs b/Orm/Xtensive.Orm.Tests/Model/CyclicHierarchyDependenciesTest.cs
index 118f495418..470dc51ed2 100644
--- a/Orm/Xtensive.Orm.Tests/Model/CyclicHierarchyDependenciesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/CyclicHierarchyDependenciesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.12.12
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Model/DuplicatedIndexDueToGenericInterfaceTest.cs b/Orm/Xtensive.Orm.Tests/Model/DuplicatedIndexDueToGenericInterfaceTest.cs
index 5819e1227f..85e03ca729 100644
--- a/Orm/Xtensive.Orm.Tests/Model/DuplicatedIndexDueToGenericInterfaceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/DuplicatedIndexDueToGenericInterfaceTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.11
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Model.DuplicatedIndexDueToGenericInterfaceTestModel;
 
diff --git a/Orm/Xtensive.Orm.Tests/Model/FieldConverterTest.cs b/Orm/Xtensive.Orm.Tests/Model/FieldConverterTest.cs
index cd4266c31a..eb00533705 100644
--- a/Orm/Xtensive.Orm.Tests/Model/FieldConverterTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/FieldConverterTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.20
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.IO;
diff --git a/Orm/Xtensive.Orm.Tests/Model/FullText/DynamicallyDefinedFieldsAndIndexesTest.cs b/Orm/Xtensive.Orm.Tests/Model/FullText/DynamicallyDefinedFieldsAndIndexesTest.cs
index baa2956ed1..b0aeb332ca 100644
--- a/Orm/Xtensive.Orm.Tests/Model/FullText/DynamicallyDefinedFieldsAndIndexesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/FullText/DynamicallyDefinedFieldsAndIndexesTest.cs
@@ -4,8 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2016.11.17
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldNamingTest.cs b/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldNamingTest.cs
index c898bd1276..1e97619eae 100644
--- a/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldNamingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldNamingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2016.11.15
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldTest.cs b/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldTest.cs
index 2f8292abb2..696a46de21 100644
--- a/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/FullText/IndexOnStructureFieldTest.cs
@@ -4,7 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2016.11.15
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Model/HierarchyTest.cs b/Orm/Xtensive.Orm.Tests/Model/HierarchyTest.cs
index 2347edf955..53bbf137bc 100644
--- a/Orm/Xtensive.Orm.Tests/Model/HierarchyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/HierarchyTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.12.26
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Model/InheritanceSchemaTest.cs b/Orm/Xtensive.Orm.Tests/Model/InheritanceSchemaTest.cs
index ae90342c9a..1c5304b08e 100644
--- a/Orm/Xtensive.Orm.Tests/Model/InheritanceSchemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/InheritanceSchemaTest.cs
@@ -4,14 +4,12 @@
 // Created by: Alexey Kochetov
 // Created:    2007.11.30
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Tests.Model.InheritanceSchemaModel;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Model.InheritanceSchemaModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Model/InheritedKeyFieldTest.cs b/Orm/Xtensive.Orm.Tests/Model/InheritedKeyFieldTest.cs
index 02ddeb514d..ab9aff2f9d 100644
--- a/Orm/Xtensive.Orm.Tests/Model/InheritedKeyFieldTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/InheritedKeyFieldTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.12.12
 
-using System;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
 using InheritedKeyFieldModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/InterfaceAssociationsModelGenerator.cs b/Orm/Xtensive.Orm.Tests/Model/InterfaceAssociationsModelGenerator.cs
index 4dce149db2..a2d8c742ad 100644
--- a/Orm/Xtensive.Orm.Tests/Model/InterfaceAssociationsModelGenerator.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/InterfaceAssociationsModelGenerator.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 
diff --git a/Orm/Xtensive.Orm.Tests/Model/LibraryTest.cs b/Orm/Xtensive.Orm.Tests/Model/LibraryTest.cs
index 47f1fd7801..5d32bb367e 100644
--- a/Orm/Xtensive.Orm.Tests/Model/LibraryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/LibraryTest.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Model/MultidatabaseKeysTest.cs b/Orm/Xtensive.Orm.Tests/Model/MultidatabaseKeysTest.cs
index 4eb8f34b19..c3603c1c6d 100644
--- a/Orm/Xtensive.Orm.Tests/Model/MultidatabaseKeysTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/MultidatabaseKeysTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.02.07
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Model/NameBuilderTest.cs b/Orm/Xtensive.Orm.Tests/Model/NameBuilderTest.cs
index 60a641961f..3b91482093 100644
--- a/Orm/Xtensive.Orm.Tests/Model/NameBuilderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/NameBuilderTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2020.02.06
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
@@ -14,7 +13,6 @@
 using Xtensive.Orm.Weaving;
 using Xtensive.Reflection;
 using Xtensive.Orm.Building.Definitions;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Model.NameBuilderTestModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Model/NonPublicFieldTest.cs b/Orm/Xtensive.Orm.Tests/Model/NonPublicFieldTest.cs
index cb7c1c8484..943b30b81f 100644
--- a/Orm/Xtensive.Orm.Tests/Model/NonPublicFieldTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/NonPublicFieldTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.14
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.NonPublicFieldTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/OnRemoveActionForNonPairedAssociationsTest.cs b/Orm/Xtensive.Orm.Tests/Model/OnRemoveActionForNonPairedAssociationsTest.cs
index f40877081a..cc4dde7a06 100644
--- a/Orm/Xtensive.Orm.Tests/Model/OnRemoveActionForNonPairedAssociationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/OnRemoveActionForNonPairedAssociationsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.26
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.OnRemoveActionForNonPairedAssociationsTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/PairTest.cs b/Orm/Xtensive.Orm.Tests/Model/PairTest.cs
index b495d91851..49fb26fa0e 100644
--- a/Orm/Xtensive.Orm.Tests/Model/PairTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/PairTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.09
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.PairModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/PersistentPropertyWeavingTest.cs b/Orm/Xtensive.Orm.Tests/Model/PersistentPropertyWeavingTest.cs
index 355b99958d..0c19dfe53a 100644
--- a/Orm/Xtensive.Orm.Tests/Model/PersistentPropertyWeavingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/PersistentPropertyWeavingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.13
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.PersistentPropertyWeavingTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/ReferencedKeys.cs b/Orm/Xtensive.Orm.Tests/Model/ReferencedKeys.cs
index c126d361cd..e575afc8dd 100644
--- a/Orm/Xtensive.Orm.Tests/Model/ReferencedKeys.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/ReferencedKeys.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.ReferencedKeysModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/SelfContainedStructureTest.cs b/Orm/Xtensive.Orm.Tests/Model/SelfContainedStructureTest.cs
index 6c6e340989..c3a37b37dd 100644
--- a/Orm/Xtensive.Orm.Tests/Model/SelfContainedStructureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/SelfContainedStructureTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.12.12
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Model/StringKeyTest.cs b/Orm/Xtensive.Orm.Tests/Model/StringKeyTest.cs
index 8b59bd9844..785f7453d0 100644
--- a/Orm/Xtensive.Orm.Tests/Model/StringKeyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/StringKeyTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.StringKeyTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/UselessTypeInTheMiddleTest.cs b/Orm/Xtensive.Orm.Tests/Model/UselessTypeInTheMiddleTest.cs
index 13e31c8211..852f82fd5e 100644
--- a/Orm/Xtensive.Orm.Tests/Model/UselessTypeInTheMiddleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/UselessTypeInTheMiddleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.03.04
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Model.UselessTypeInTheMiddleTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Model/VersionInfoTest.cs b/Orm/Xtensive.Orm.Tests/Model/VersionInfoTest.cs
index ac6139ae9b..452a63bc7b 100644
--- a/Orm/Xtensive.Orm.Tests/Model/VersionInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Model/VersionInfoTest.cs
@@ -5,11 +5,9 @@
 // Created:    2009.08.13
 
 using System.Reflection;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
-using System;
 
 #region Models
 
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Chinook.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Chinook.cs
index 4653172bb7..d9fa1e21ce 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Chinook.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Chinook.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Kudelin
 // Created:    2019.09.19
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Tests.ObjectModel.ChinookDO
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDO.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDO.cs
index 08d414c179..91b5199e65 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDO.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDO.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Kudelin
 // Created:    2019.09.19
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Xml.Linq;
 using Xtensive.Orm.Configuration;
 using IdEntity = System.ValueTuple<int,Xtensive.Orm.Entity>;
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDOModelTest.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDOModelTest.cs
index 3c5b505461..f1ec411047 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDOModelTest.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/ChinookDOModelTest.cs
@@ -5,9 +5,6 @@
 // Created:    2019.09.19
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/AscxTemplate.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/AscxTemplate.cs
index d6a984433d..e04f8c5ca4 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/AscxTemplate.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/AscxTemplate.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.09.16
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentDirectory.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentDirectory.cs
index c26a2cf85c..e26826084a 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentDirectory.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentDirectory.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.08.31
 
-using System;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentFile.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentFile.cs
index 8e7523c00b..561953562d 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentFile.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentFile.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.08.31
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentItem.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentItem.cs
index 764b8e56b2..e4c01072ca 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentItem.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentItem.cs
@@ -5,7 +5,6 @@
 // Created:    2009.08.31
 
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentReference.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentReference.cs
index 3d1132a6d3..0b89fbf702 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentReference.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/ContentReference.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.12.14
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/HtmlContentItem.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/HtmlContentItem.cs
index a84e2f9d02..51ed8c874a 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/HtmlContentItem.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/HtmlContentItem.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.09.15
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Menu.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Menu.cs
index 4b1163de35..3aedd48bf9 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Menu.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Menu.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.09.16
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsDirectory.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsDirectory.cs
index 7a153857d8..6f5fe65caf 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsDirectory.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsDirectory.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.12.14
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsList.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsList.cs
index bff6bfd7fb..98b12b7400 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsList.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsList.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.12.14
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsPage.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsPage.cs
index 8eb7649536..f01c181e85 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsPage.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/NewsPage.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.12.14
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Page.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Page.cs
index 524821150e..5b883d9d57 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Page.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/Page.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.08.31
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/PageTemplate.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/PageTemplate.cs
index f60ddcdaeb..a49b63cd9d 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/PageTemplate.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/PageTemplate.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.08.31
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSite.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSite.cs
index 240f191472..7944b7a960 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSite.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSite.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.08.31
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSiteUrl.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSiteUrl.cs
index 4963719b56..ca81a618c7 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSiteUrl.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Cms/WebSiteUrl.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2009.09.08
 
-using System;
 using Xtensive.Orm.Validation;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Cms
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/GenericModel.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/GenericModel.cs
index 63c4df96fd..7fd0458913 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/GenericModel.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/GenericModel.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.07
 
-using System;
 
 namespace Xtensive.Orm.Tests.ObjectModel.GenericModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/GraphModel.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/GraphModel.cs
index 34efe7cfee..8357aefdf8 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/GraphModel.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/GraphModel.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.29
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.ObjectModel.GraphModel
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Alphabet.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Alphabet.cs
index a988f35b1b..e34ee5d0ea 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Alphabet.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Alphabet.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.24
 
-using System;
 using System.Diagnostics;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Slavery.cs b/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Slavery.cs
index 21e7f2e907..b8e5423304 100644
--- a/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Slavery.cs
+++ b/Orm/Xtensive.Orm.Tests/ObjectModel/Interfaces/Slavery.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.24
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.ObjectModel.Interfaces.Slavery
diff --git a/Orm/Xtensive.Orm.Tests/Rse/IncludeProviderTest.cs b/Orm/Xtensive.Orm.Tests/Rse/IncludeProviderTest.cs
index 68be0ec15a..6d9d149e8c 100644
--- a/Orm/Xtensive.Orm.Tests/Rse/IncludeProviderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Rse/IncludeProviderTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.27
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AbstractGenericsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AbstractGenericsTest.cs
index ea4e24276b..af5cf9f72e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AbstractGenericsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AbstractGenericsTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.03
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Storage.AbstractGenericTest_Model;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ActivatorTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ActivatorTest.cs
index a53fa6eb4c..fa39715a07 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ActivatorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ActivatorTest.cs
@@ -4,12 +4,10 @@
 // Created by: Nick Svetlov
 // Created:    2008.06.11
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ActivatorModel;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Storage.ActivatorModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AggregateTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AggregateTest.cs
index 49735b3405..865ac4b764 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AggregateTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AggregateTest.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.28
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
-using System;
 
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.DbTypeSupportModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AnotherValidationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AnotherValidationTest.cs
index a5328dbd76..6aadd61a7c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AnotherValidationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AnotherValidationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.10.30
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Validation;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ApplyTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ApplyTest.cs
index c5173aefee..c629972e2d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ApplyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ApplyTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.03.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncExtensionsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncExtensionsTest.cs
index 4d94159fb7..eb432d624a 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncExtensionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncExtensionsTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.AsyncQueries.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncQueryBaseTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncQueryBaseTest.cs
index a843c1e010..a5a87e79f7 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncQueryBaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/AsyncQueryBaseTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.AsyncQueries.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ClientProfileTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ClientProfileTest.cs
index 6291086424..c046454ea9 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ClientProfileTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ClientProfileTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ServerProfileTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ServerProfileTest.cs
index 112d9b2568..c45f3d099d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ServerProfileTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Compiled/ServerProfileTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryClientProfileTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryClientProfileTest.cs
index 2c8cd80cc9..76faf33133 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryClientProfileTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryClientProfileTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.AsyncQueries.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryServerProfileTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryServerProfileTest.cs
index 81a218e7cf..2f01be811b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryServerProfileTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryServerProfileTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.AsyncQueries.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryTestBase.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryTestBase.cs
index 132248aba6..b729fb933c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/DelayedQueryTestBase.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/ExecuteAsyncExtensionTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/ExecuteAsyncExtensionTest.cs
index 33787b34a6..815a796c01 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/ExecuteAsyncExtensionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/ExecuteAsyncExtensionTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.09.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Model.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Model.cs
index 5e4c4fe93c..ced0b9584e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.07.01
 
-using System;
 
 namespace Xtensive.Orm.Tests.Storage.AsyncQueries.Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/PersistWithAsyncQueriesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/PersistWithAsyncQueriesTest.cs
index f49da19c67..ffb0ee3f85 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/PersistWithAsyncQueriesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncQueries/PersistWithAsyncQueriesTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.07.12
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/AsyncSession/AsyncSessionOpeningTest.cs b/Orm/Xtensive.Orm.Tests/Storage/AsyncSession/AsyncSessionOpeningTest.cs
index 288a901cd7..acc833fe88 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/AsyncSession/AsyncSessionOpeningTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/AsyncSession/AsyncSessionOpeningTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.07.12
 
-using System;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/BatchingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/BatchingTest.cs
index b5507c976a..681ca40dcb 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/BatchingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/BatchingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.18
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ByteFieldStorageTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ByteFieldStorageTest.cs
index 83099f9121..f250c8c37c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ByteFieldStorageTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ByteFieldStorageTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.12.17
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CascadeRemoveTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CascadeRemoveTest.cs
index f3db11399f..6769c24bec 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CascadeRemoveTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CascadeRemoveTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.24
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.CascadeRemoveTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ChangedPersistOrderTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ChangedPersistOrderTest.cs
index 678852261e..c1447e8a9c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ChangedPersistOrderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ChangedPersistOrderTest.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using model = Xtensive.Orm.Tests.Storage.ChangedPersistOrderTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ClientProfileReferentialIntegrityTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ClientProfileReferentialIntegrityTest.cs
index ace8624295..f6178d8f59 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ClientProfileReferentialIntegrityTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ClientProfileReferentialIntegrityTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.02.12
 
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ClientProfileSessionTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ClientProfileSessionTest.cs
index 5d461bae70..964eab788c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ClientProfileSessionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ClientProfileSessionTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.09.14
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ClosureParametersCachingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ClosureParametersCachingTest.cs
index 5c53923e74..ffd315b9bd 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ClosureParametersCachingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ClosureParametersCachingTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.10.26
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ClusteredIndexesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ClusteredIndexesTest.cs
index 620876bc67..1461d23543 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ClusteredIndexesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ClusteredIndexesTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 //using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CmsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CmsTest.cs
index b40fd0c6bc..b918b69377 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CmsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CmsTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.16
 
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingCommandProcessorParametersManagement.cs b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingCommandProcessorParametersManagement.cs
index f07dc0d37d..029d847206 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingCommandProcessorParametersManagement.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingCommandProcessorParametersManagement.cs
@@ -2,10 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingOfVersionizedEntitiesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingOfVersionizedEntitiesTest.cs
index 1715f87a9a..5dd29a1f34 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingOfVersionizedEntitiesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/BatchingOfVersionizedEntitiesTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/ParametersManagementModel.cs b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/ParametersManagementModel.cs
index 7c416e3bc6..483033698d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/ParametersManagementModel.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/ParametersManagementModel.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/SimpleCommandProcessorParametersManagement.cs b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/SimpleCommandProcessorParametersManagement.cs
index c55f06c5b3..cbae0f5b7d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/SimpleCommandProcessorParametersManagement.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CommandProcessing/SimpleCommandProcessorParametersManagement.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.04.14
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CompiledQueryTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CompiledQueryTest.cs
index 61dfbab87c..ee97acfe8a 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CompiledQueryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CompiledQueryTest.cs
@@ -4,13 +4,10 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
-using System.Linq;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Storage
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ConnectionAccessorTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ConnectionAccessorTest.cs
index 41d42876ba..25b9b34ee4 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ConnectionAccessorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ConnectionAccessorTest.cs
@@ -2,17 +2,13 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
 using Xtensive.Orm.Tests.Storage.ConnectionAccessorsModel;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Storage.ConnectionAccessorsModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CoreServicesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CoreServicesTest.cs
index 3faa88ec44..c728f37e08 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CoreServicesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CoreServicesTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.03
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CustomCollationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CustomCollationTest.cs
index 6dfd4a27c1..1b65c5e7fe 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CustomCollationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CustomCollationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.05
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.CustomCollationTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CustomEntitySetTest.cs b/Orm/Xtensive.Orm.Tests/Storage/CustomEntitySetTest.cs
index 7487777e4b..7821a545f8 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CustomEntitySetTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CustomEntitySetTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.07
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Tests.Storage.CustomEntitySetModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/CustomMetadataUpgrade.cs b/Orm/Xtensive.Orm.Tests/Storage/CustomMetadataUpgrade.cs
index b105da258f..65b898cf8a 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/CustomMetadataUpgrade.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/CustomMetadataUpgrade.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.29
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Metadata;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DataErrorInfo.cs b/Orm/Xtensive.Orm.Tests/Storage/DataErrorInfo.cs
index 9678e5f01c..6f5a4acf04 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DataErrorInfo.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DataErrorInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.09.17
 
-using System;
 using System.ComponentModel;
 using NUnit.Framework;
 using Xtensive.Orm.Validation;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DateTimeStoragePrecisionTest.cs b/Orm/Xtensive.Orm.Tests/Storage/DateTimeStoragePrecisionTest.cs
index dfbc14fc69..5589c4a8ca 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DateTimeStoragePrecisionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DateTimeStoragePrecisionTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.DateTimeStoragePrecisionTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DirectSqlTest.cs b/Orm/Xtensive.Orm.Tests/Storage/DirectSqlTest.cs
index a950aef90b..e62fc3eee3 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DirectSqlTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DirectSqlTest.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.29
 
-using System;
 using System.Data.Common;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DisableIndexOnReferenceFieldTest.cs b/Orm/Xtensive.Orm.Tests/Storage/DisableIndexOnReferenceFieldTest.cs
index eaa54e3a57..9ddd4dc6f6 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DisableIndexOnReferenceFieldTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DisableIndexOnReferenceFieldTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.05
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DisableSaveChangesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/DisableSaveChangesTest.cs
index 8c6fa7b6be..90fd37ca5f 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DisableSaveChangesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DisableSaveChangesTest.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.11
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
-using System;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.DisableSaveChangesTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DisableValidationAndImplicitConstraintsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/DisableValidationAndImplicitConstraintsTest.cs
index a3dada4d99..7bb1333fc3 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DisableValidationAndImplicitConstraintsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DisableValidationAndImplicitConstraintsTest.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.DisableValidationAndImplicitConstraintsTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/DuplicateIndexTest.cs b/Orm/Xtensive.Orm.Tests/Storage/DuplicateIndexTest.cs
index d78d81a8c6..2107bb6b03 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/DuplicateIndexTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/DuplicateIndexTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.04
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/EntityChangeRegistryTest.cs b/Orm/Xtensive.Orm.Tests/Storage/EntityChangeRegistryTest.cs
index 08f3ccade5..77dac50c3b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/EntityChangeRegistryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/EntityChangeRegistryTest.cs
@@ -5,9 +5,6 @@
 // Created:    2020.02.14
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/EntitySetRollbackTest.cs b/Orm/Xtensive.Orm.Tests/Storage/EntitySetRollbackTest.cs
index e0f23ca74f..8eae5c8170 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/EntitySetRollbackTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/EntitySetRollbackTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.03.03
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.EntitySetRollbackTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/EntitySetTest.cs b/Orm/Xtensive.Orm.Tests/Storage/EntitySetTest.cs
index 64baf196c8..51d19a90ed 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/EntitySetTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/EntitySetTest.cs
@@ -4,9 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.03.11
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ExecuteDelayedForIOrderedQueryableQuery.cs b/Orm/Xtensive.Orm.Tests/Storage/ExecuteDelayedForIOrderedQueryableQuery.cs
index f05d0cfd9f..e1a3b7d660 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ExecuteDelayedForIOrderedQueryableQuery.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ExecuteDelayedForIOrderedQueryableQuery.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.06.23
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Linq.ExecuteDelayedForIOrderedQueryableQueryModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/FailedQueryAndDbCommandNotificationsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/FailedQueryAndDbCommandNotificationsTest.cs
index ec1488a888..4c551e2d6a 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/FailedQueryAndDbCommandNotificationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/FailedQueryAndDbCommandNotificationsTest.cs
@@ -4,8 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2017.02.08
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.FailedQueryAndDbCommandNotificationsTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/FieldDefaultValueTest.cs b/Orm/Xtensive.Orm.Tests/Storage/FieldDefaultValueTest.cs
index e6681ffabf..aefdb9599a 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/FieldDefaultValueTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/FieldDefaultValueTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.19
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/FieldSqlDefaultTest.cs b/Orm/Xtensive.Orm.Tests/Storage/FieldSqlDefaultTest.cs
index a05604b1ad..2931bf0f3b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/FieldSqlDefaultTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/FieldSqlDefaultTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.02.26
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ForceServerVersion.cs b/Orm/Xtensive.Orm.Tests/Storage/ForceServerVersion.cs
index 0a275e8c04..4e1a9bee6e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ForceServerVersion.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ForceServerVersion.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.06
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ForeignKeyTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ForeignKeyTest.cs
index 0200166113..7cb801dbad 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ForeignKeyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ForeignKeyTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.IoC;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/FutureTest.cs b/Orm/Xtensive.Orm.Tests/Storage/FutureTest.cs
index 620d0cc3a2..c340315480 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/FutureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/FutureTest.cs
@@ -4,11 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/GeneralBehaviorTest.cs b/Orm/Xtensive.Orm.Tests/Storage/GeneralBehaviorTest.cs
index 6732b7de71..8ac1e0c99d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/GeneralBehaviorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/GeneralBehaviorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2010.02.17
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Storage.GeneralBehaviorTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/GenericTest.cs b/Orm/Xtensive.Orm.Tests/Storage/GenericTest.cs
index b39f6b8404..0f5bf78189 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/GenericTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/GenericTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.03.12
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesConfigureTest.cs b/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesConfigureTest.cs
index 15dd6d3311..e11d5e9ce5 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesConfigureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesConfigureTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesHandlerTest.cs b/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesHandlerTest.cs
index 572309892e..4cf1a2d3f6 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesHandlerTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesHandlerTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesValidateTest.cs b/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesValidateTest.cs
index 144d6cf2c3..be4422d977 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesValidateTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IgnoreRulesValidateTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IntermediateQueryTest.cs b/Orm/Xtensive.Orm.Tests/Storage/IntermediateQueryTest.cs
index 00be2cc4a1..c8d2e5284f 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IntermediateQueryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IntermediateQueryTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.11.17
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IoC/ProxyContainerBase.cs b/Orm/Xtensive.Orm.Tests/Storage/IoC/ProxyContainerBase.cs
index 55eca7915d..b170ba8818 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IoC/ProxyContainerBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IoC/ProxyContainerBase.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.11
 
-using System;
-using System.Collections.Generic;
 using Xtensive.IoC;
 
 namespace Xtensive.Orm.Tests.Storage.IoC
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IoC/QueryFormatterServiceTest.cs b/Orm/Xtensive.Orm.Tests/Storage/IoC/QueryFormatterServiceTest.cs
index eb703b9165..7a5dcad49c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IoC/QueryFormatterServiceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IoC/QueryFormatterServiceTest.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.03.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/IoC/ServiceTestBase.cs b/Orm/Xtensive.Orm.Tests/Storage/IoC/ServiceTestBase.cs
index a44216408f..5d04a07f4e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/IoC/ServiceTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/IoC/ServiceTestBase.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.16
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.IoC.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/KeysTest.cs b/Orm/Xtensive.Orm.Tests/Storage/KeysTest.cs
index 7c1c3de0d8..69fa64dac2 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/KeysTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/KeysTest.cs
@@ -4,7 +4,6 @@
 // Created by: 
 // Created:    2008.09.17
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.Keys;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/LazyLoadTest.cs b/Orm/Xtensive.Orm.Tests/Storage/LazyLoadTest.cs
index f95e7c90bf..087c6a4b2d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/LazyLoadTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/LazyLoadTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.06.26
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/AnimalDbBaseTest.cs b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/AnimalDbBaseTest.cs
index 04d26ccd21..960c9408c4 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/AnimalDbBaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/AnimalDbBaseTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.26
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/ContainerItemTest.cs b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/ContainerItemTest.cs
index e23e913781..f6e19b4407 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/ContainerItemTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/ContainerItemTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.26
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.LegacyDb.ContainerItemModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2005Test.cs b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2005Test.cs
index 439845b22f..8d2c7a58ee 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2005Test.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2005Test.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.03.03
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.LegacyDb.CrazyColumns2005TestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2008Test.cs b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2008Test.cs
index ecb1e17703..c5238cb7e6 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2008Test.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/LegacyDb/CrazyColumns2008Test.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.LegacyDb.CrazyColumns2008TestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ManyToManyValidationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ManyToManyValidationTest.cs
index 702f7e5f41..645fa16441 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ManyToManyValidationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ManyToManyValidationTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.11.10
 
-using System;
-using System.Linq;
 using System.Runtime.Serialization;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/MemoryProviderTest.cs b/Orm/Xtensive.Orm.Tests/Storage/MemoryProviderTest.cs
index 672c4a00d8..c5a6e6605a 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/MemoryProviderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/MemoryProviderTest.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.02.14
 
-using System;
 using System.Data;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly0.cs b/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly0.cs
index 5e43cc8c78..48026a7d0b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly0.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly0.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.03
 
-using System;
 using System.Diagnostics;
 using Xtensive.Orm;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly1.cs b/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly1.cs
index 1e456dae45..f5d2c2ae70 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly1.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly1.cs
@@ -4,9 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.03
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Orm;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly2.cs b/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly2.cs
index 8fe613592c..0c49df0f48 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly2.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Modules/Assembly2.cs
@@ -4,9 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.03
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Orm;
 using Xtensive.Orm.Building;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Modules/ModulesRegistrationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Modules/ModulesRegistrationTest.cs
index 5b7073d289..4b4bd171df 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Modules/ModulesRegistrationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Modules/ModulesRegistrationTest.cs
@@ -4,10 +4,8 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.03
 
-using System;
 using System.CodeDom.Compiler;
 using System.IO;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CaseSensitiveSchemasTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CaseSensitiveSchemasTest.cs
index 8234eb3e7d..8e65992541 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CaseSensitiveSchemasTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CaseSensitiveSchemasTest.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using M = Xtensive.Orm.Tests.Storage.Multimapping.CaseSensitiveSchemasTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossDatabaseTableMoveTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossDatabaseTableMoveTest.cs
index 2399b8a2a6..0e2d105d44 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossDatabaseTableMoveTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossDatabaseTableMoveTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.16
 
-using System.Linq;
 using NUnit.Framework;
 using V1 = Xtensive.Orm.Tests.Storage.Multimapping.CrossRenameModel.Version1;
 using V2 = Xtensive.Orm.Tests.Storage.Multimapping.CrossRenameModel.Version2;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossRenameModel/Version2/UpgradeHandler.cs b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossRenameModel/Version2/UpgradeHandler.cs
index 99f47b4ecf..350f7e962c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossRenameModel/Version2/UpgradeHandler.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossRenameModel/Version2/UpgradeHandler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.16
 
-using System.Collections.Generic;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Tests.Storage.Multimapping.CrossRenameModel.Version2
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossSchemaTableMoveTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossSchemaTableMoveTest.cs
index 35a1287db3..f23ab9773e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossSchemaTableMoveTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CrossSchemaTableMoveTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.16
 
-using System.Linq;
 using NUnit.Framework;
 using V1 = Xtensive.Orm.Tests.Storage.Multimapping.CrossRenameModel.Version1;
 using V2 = Xtensive.Orm.Tests.Storage.Multimapping.CrossRenameModel.Version2;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CycleReferencesDetectionTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CycleReferencesDetectionTest.cs
index 6db8a9f812..6131044ebf 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CycleReferencesDetectionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/CycleReferencesDetectionTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.14
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Storage.Multimapping.CycleReferencesDetectionModel.Namespace1;
 using Xtensive.Orm.Tests.Storage.Multimapping.CycleReferencesDetectionModel.Namespace2;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/InterfaceAndAssociationMappingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/InterfaceAndAssociationMappingTest.cs
index 84d0859d12..74dec75152 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multimapping/InterfaceAndAssociationMappingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multimapping/InterfaceAndAssociationMappingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.11.14
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Storage.Multimapping.InterfaceAndAssociationMappingTestModel.Entities;
 using Xtensive.Orm.Tests.Storage.Multimapping.InterfaceAndAssociationMappingTestModel.Interfaces;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/ConnectionOverrideTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/ConnectionOverrideTest.cs
index b6db1e359d..f878233b78 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/ConnectionOverrideTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/ConnectionOverrideTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/DynamicTypeIdTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/DynamicTypeIdTest.cs
index 4053ed9d10..cf6e6e0ebe 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/DynamicTypeIdTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/DynamicTypeIdTest.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/InitializationSqlOverrideTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/InitializationSqlOverrideTest.cs
index 313cab6ffc..3bf291a79b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/InitializationSqlOverrideTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/InitializationSqlOverrideTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/QueryCachingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/QueryCachingTest.cs
index 8a03700bda..cec50b4b27 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/QueryCachingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/QueryCachingTest.cs
@@ -5,9 +5,6 @@
 // Created:    2019.01.28
 
 using NUnit.Framework;
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.Multinode.QueryCachingTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/StaleQueryCacheForReAddedNodes.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/StaleQueryCacheForReAddedNodes.cs
index 9b1a14a815..73f827ac74 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/StaleQueryCacheForReAddedNodes.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/StaleQueryCacheForReAddedNodes.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/StandardMultinodeTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/StandardMultinodeTest.cs
index 69b451b891..fd2545ba39 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/StandardMultinodeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/StandardMultinodeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.26
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.Keys;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/StorageNodeManagerTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/StorageNodeManagerTest.cs
index 1d9617ac4f..8e42a6871b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/StorageNodeManagerTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/StorageNodeManagerTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Multinode/TypeIdAllocationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Multinode/TypeIdAllocationTest.cs
index c2e0da11a8..1f77e70bb1 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Multinode/TypeIdAllocationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Multinode/TypeIdAllocationTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.12.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/NestedTransactionsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/NestedTransactionsTest.cs
index 520ec616d2..b17a12c3da 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/NestedTransactionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/NestedTransactionsTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.26
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/NewProfilesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/NewProfilesTest.cs
index f09a43aca4..2297685cb5 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/NewProfilesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/NewProfilesTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.04.14
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/NonPersistentCompositeObjectTest.cs b/Orm/Xtensive.Orm.Tests/Storage/NonPersistentCompositeObjectTest.cs
index 4a490baaaa..08cd0537c6 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/NonPersistentCompositeObjectTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/NonPersistentCompositeObjectTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.10.13
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/NonTransactionalEntityAccess.cs b/Orm/Xtensive.Orm.Tests/Storage/NonTransactionalEntityAccess.cs
index 975ec65ff6..67c8eeb49b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/NonTransactionalEntityAccess.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/NonTransactionalEntityAccess.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.01.30
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.TransactionsTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/NotifyPropertyChangedTest.cs b/Orm/Xtensive.Orm.Tests/Storage/NotifyPropertyChangedTest.cs
index f5e5a6a6a8..ad8aae5627 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/NotifyPropertyChangedTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/NotifyPropertyChangedTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.02
 
-using System;
 using System.ComponentModel;
 using System.Reflection;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/NotifyXxxTest.cs b/Orm/Xtensive.Orm.Tests/Storage/NotifyXxxTest.cs
index 4baee1087e..819ac67ae7 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/NotifyXxxTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/NotifyXxxTest.cs
@@ -4,10 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
 using System.Collections.Specialized;
 using System.ComponentModel;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/OnRemovingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/OnRemovingTest.cs
index 28194652c4..a25dae7359 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/OnRemovingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/OnRemovingTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.21
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.OnRemovingTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/OperationOrderTest.cs b/Orm/Xtensive.Orm.Tests/Storage/OperationOrderTest.cs
index 5c5e97146c..a76ae41483 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/OperationOrderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/OperationOrderTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.12
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 
@@ -13,7 +12,6 @@
 using Xtensive.Reflection;
 using Xtensive.Orm.Operations;
 using Xtensive.Core;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Storage.OperationOrderTest
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/OverrideConnectionInfoTest.cs b/Orm/Xtensive.Orm.Tests/Storage/OverrideConnectionInfoTest.cs
index e81127f148..bbe68a82f4 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/OverrideConnectionInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/OverrideConnectionInfoTest.cs
@@ -1,4 +1,4 @@
-// Copyright (C) 2014 Xtensive LLC.
+// Copyright (C) 2014 Xtensive LLC.
 // All rights reserved.
 // For conditions of distribution and use, see license.
 // Created by: Denis Krjuchkov
@@ -6,6 +6,7 @@
 
 using NUnit.Framework;
 using Xtensive.Orm.Metadata;
+using Type = Xtensive.Orm.Metadata.Type;
 
 namespace Xtensive.Orm.Tests.Storage
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/OverrideMetadata.cs b/Orm/Xtensive.Orm.Tests/Storage/OverrideMetadata.cs
index 27f71d41b7..5052b78b8d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/OverrideMetadata.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/OverrideMetadata.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.28
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/PartialIndexTest.cs b/Orm/Xtensive.Orm.Tests/Storage/PartialIndexTest.cs
index 2a8bf8cbd5..82f5446569 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/PartialIndexTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/PartialIndexTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/NonPairedSimplestContainerItem.cs b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/NonPairedSimplestContainerItem.cs
index e1f06a2f5d..c8c9f10c04 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/NonPairedSimplestContainerItem.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/NonPairedSimplestContainerItem.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.04
 
-using System;
 
 namespace Xtensive.Orm.Tests.Storage.Performance.CrudModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/PairedSimplestContainerItem.cs b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/PairedSimplestContainerItem.cs
index b5e1dcd150..98a5e14428 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/PairedSimplestContainerItem.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/PairedSimplestContainerItem.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.04
 
-using System;
 
 namespace Xtensive.Orm.Tests.Storage.Performance.CrudModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/Simplest.cs b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/Simplest.cs
index a1fc174191..7cddec12f0 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/Simplest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/Simplest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.09.23
 
-using System;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/SimplestContainer.cs b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/SimplestContainer.cs
index 5569524b3c..badaf09513 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/SimplestContainer.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Performance/CrudModel/SimplestContainer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.03
 
-using System;
 
 namespace Xtensive.Orm.Tests.Storage.Performance.CrudModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Performance/DoCrudTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Performance/DoCrudTest.cs
index 8ca0503f82..63421c6931 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Performance/DoCrudTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Performance/DoCrudTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Performance/SqlClientCrudTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Performance/SqlClientCrudTest.cs
index 77b1a85ee9..5d9c7d04cb 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Performance/SqlClientCrudTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Performance/SqlClientCrudTest.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.19
 
-using System.Collections.Generic;
 using Microsoft.Data.SqlClient;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/PersistTest.cs b/Orm/Xtensive.Orm.Tests/Storage/PersistTest.cs
index 9ef3613c2c..3de16628f7 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/PersistTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/PersistTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.01
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/PostgreSqlSpatialTest.cs b/Orm/Xtensive.Orm.Tests/Storage/PostgreSqlSpatialTest.cs
index 2227a7f4ea..a8d2b34dd4 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/PostgreSqlSpatialTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/PostgreSqlSpatialTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.04.09
 
-using System;
-using System.Linq;
 using NpgsqlTypes;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/Model.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/Model.cs
index 3a5e6e3668..630c092239 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/Model.cs
@@ -4,10 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.10
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Storage.Prefetch.Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchDelayedElementsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchDelayedElementsTest.cs
index b93aaa48ee..db156eea5d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchDelayedElementsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchDelayedElementsTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.07
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerAdvancedTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerAdvancedTest.cs
index 13ae8c9979..2ab975b21c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerAdvancedTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerAdvancedTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.26
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerBasicTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerBasicTest.cs
index ca375845f8..4732ee63a4 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerBasicTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerBasicTest.cs
@@ -4,11 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.07
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Runtime.CompilerServices;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerTestBase.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerTestBase.cs
index 428918644b..d03839a3dc 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchManagerTestBase.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTest.cs
index ccb73d9415..3ce2b51a3f 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTestHelper.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTestHelper.cs
index d573a73681..ea126d7432 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTestHelper.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchTestHelper.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchWithSmallCacheTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchWithSmallCacheTest.cs
index f866abf4e2..484491fccc 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchWithSmallCacheTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Prefetch/PrefetchWithSmallCacheTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/BooleanHandlingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/BooleanHandlingTest.cs
index aa572d1e1d..5d6e73c44d 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/BooleanHandlingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/BooleanHandlingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.03.20
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CharSupportTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CharSupportTest.cs
index 9103bbf4c1..5d9486f752 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CharSupportTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CharSupportTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.20
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CustomConnectionInfoTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CustomConnectionInfoTest.cs
index 93076ed504..58c8b597a4 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CustomConnectionInfoTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/CustomConnectionInfoTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.06.10
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Metadata;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/NullValuesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/NullValuesTest.cs
index a7c8c7fd7b..379ca89a8b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/NullValuesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/NullValuesTest.cs
@@ -5,8 +5,6 @@
 // Created:    2009.04.25
 
 using NUnit.Framework;
-using System.Collections.Generic;
-using System.Linq;
 
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/RoundingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/RoundingTest.cs
index fdac9a83a1..f0cd0565db 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/RoundingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/RoundingTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.09
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/StringOperationsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/StringOperationsTest.cs
index 633321395f..b537002244 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/StringOperationsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/StringOperationsTest.cs
@@ -5,7 +5,6 @@
 // Created:    2009.07.13
 
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.Storage.DbTypeSupportModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TableReferenceTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TableReferenceTest.cs
index e8fca456ab..df34be3269 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TableReferenceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TableReferenceTest.cs
@@ -4,9 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.12.23
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TotalBatchingTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TotalBatchingTest.cs
index e253919499..6cba8d9576 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TotalBatchingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Providers/Sql/TotalBatchingTest.cs
@@ -5,8 +5,6 @@
 // Created:    2009.08.20
 
 using NUnit.Framework;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/QueryBuilderTest.cs b/Orm/Xtensive.Orm.Tests/Storage/QueryBuilderTest.cs
index f6539e57b4..9541b5df95 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/QueryBuilderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/QueryBuilderTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.27
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/QueryResultTest.cs b/Orm/Xtensive.Orm.Tests/Storage/QueryResultTest.cs
index 9c0a281801..4a72079055 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/QueryResultTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/QueryResultTest.cs
@@ -2,12 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.QueryResultTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Randomized/RandomizedTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Randomized/RandomizedTest.cs
index 34b177f292..930c5af050 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Randomized/RandomizedTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Randomized/RandomizedTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.11.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Security.Cryptography;
 using System.Transactions;
 using NUnit.Framework;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Randomized/Tree.cs b/Orm/Xtensive.Orm.Tests/Storage/Randomized/Tree.cs
index bf1378d0a6..4bd9a37e03 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Randomized/Tree.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Randomized/Tree.cs
@@ -4,9 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.11.26
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Randomized/TreeNode.cs b/Orm/Xtensive.Orm.Tests/Storage/Randomized/TreeNode.cs
index 93e09ca58a..db810fc4d7 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Randomized/TreeNode.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Randomized/TreeNode.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.11.26
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Tests.Storage.Randomized
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReadOnlySupport/ReadOnlyStorageTestBase.cs b/Orm/Xtensive.Orm.Tests/Storage/ReadOnlySupport/ReadOnlyStorageTestBase.cs
index 90fbe42056..6fb757f837 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReadOnlySupport/ReadOnlyStorageTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReadOnlySupport/ReadOnlyStorageTestBase.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2016.03.18
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReadRemovedObjectTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ReadRemovedObjectTest.cs
index d2ddec2284..ab8bae58b8 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReadRemovedObjectTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReadRemovedObjectTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/RefTest.cs b/Orm/Xtensive.Orm.Tests/Storage/RefTest.cs
index b2c86cab39..582011a64b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/RefTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/RefTest.cs
@@ -4,11 +4,9 @@
 // Created by: Alexis Kochetov
 // Created:    2010.10.01
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Storage.RefTest
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromEntitiesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromEntitiesTest.cs
index c306590c6b..e228a9a6c0 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromEntitiesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromEntitiesTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.22
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ReferentialIntegrity.ClientProfile.NonPairedReferencesFromEntitiesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromStructures.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromStructures.cs
index f105d5dbde..a1d14e8d27 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromStructures.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/NonPairedReferencesFromStructures.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.22
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/PairedReferencesFromEntitiesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/PairedReferencesFromEntitiesTest.cs
index 6846fb9c78..82a218757b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/PairedReferencesFromEntitiesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfile/PairedReferencesFromEntitiesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.23
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ReferentialIntegrity.ClientProfile.PairedReferencesFromEntitiesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromEntitiesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromEntitiesTest.cs
index 2fe9cb412b..47f78ca641 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromEntitiesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromEntitiesTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.22
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ReferentialIntegrity.ClientProfileLike.NonPairedReferencesFromEntitiesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromStructures.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromStructures.cs
index 38934c6b32..356c288ffa 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromStructures.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/NonPairedReferencesFromStructures.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.22
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/PairedReferencesFromEntitiesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/PairedReferencesFromEntitiesTest.cs
index 4d8c3b7875..b83ac3030c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/PairedReferencesFromEntitiesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrity/ClientProfileLike/PairedReferencesFromEntitiesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.23
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ReferentialIntegrity.ClientProfileLike.PairedReferencesFromEntitiesModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrityTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrityTest.cs
index d84b28ca99..800af1ce3f 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrityTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ReferentialIntegrityTest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.01
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/RemapKeysWhenLazyKeyGenerationEnabledTest.cs b/Orm/Xtensive.Orm.Tests/Storage/RemapKeysWhenLazyKeyGenerationEnabledTest.cs
index efd55383e2..6e3e5d0be8 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/RemapKeysWhenLazyKeyGenerationEnabledTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/RemapKeysWhenLazyKeyGenerationEnabledTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.04.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.RemapKeysWhenLazyKeyGenerationEnabledModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/RemoveReasonOnEntityRemovingEventTest.cs b/Orm/Xtensive.Orm.Tests/Storage/RemoveReasonOnEntityRemovingEventTest.cs
index 34cb5baa6f..7ffdd826ad 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/RemoveReasonOnEntityRemovingEventTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/RemoveReasonOnEntityRemovingEventTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.10.15
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/Model.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/Model.cs
index 49ec9306aa..deeb64cac0 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.05
 
-using System;
 
 namespace Xtensive.Orm.Tests.Storage.SchemaSharing.EntityManipulation.Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultidatabaseEntityManipulationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultidatabaseEntityManipulationTest.cs
index 21bf962276..af5d11e1c2 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultidatabaseEntityManipulationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultidatabaseEntityManipulationTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Storage.SchemaSharing.EntityManipulation.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultischemaEntityManipulationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultischemaEntityManipulationTest.cs
index d22d914b6e..795ee31a78 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultischemaEntityManipulationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/MultischemaEntityManipulationTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Storage.SchemaSharing.EntityManipulation.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/SimpleEntityManipulationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/SimpleEntityManipulationTest.cs
index 7b07cf93c7..ac64d26554 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/SimpleEntityManipulationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/EntityManipulation/SimpleEntityManipulationTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.05
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/IgnoreRulesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/IgnoreRulesTest.cs
index 85a9eb9435..ef61757f00 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/IgnoreRulesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/IgnoreRulesTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.03
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/Model.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/Model.cs
index d25c4c3939..052f0ddaf3 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/Model.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.Storage.SchemaSharing.KeyGenerator.Model
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultidatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultidatabaseTest.cs
index 574a225259..7391957a66 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultidatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultidatabaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.06
 
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultischemaTest.cs
index bb262c9543..abeb301f59 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/MultischemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.06
 
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/SimpleTest.cs
index 9ab9dde1da..11375a32b5 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/KeyGenerator/SimpleTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/Model.cs b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/Model.cs
index 79bca128f1..d4f8f5d987 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SchemaSharing/Model.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Orm.Tests.Storage.SchemaSharing.Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SerializationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SerializationTest.cs
index ccc0269dde..48d5ca1804 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SerializationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SerializationTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.03.19
 
-using System;
 using System.IO;
 using System.Reflection;
 using System.Runtime.Serialization.Formatters.Binary;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SerializedQueryTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SerializedQueryTest.cs
index a2c6e34932..21502d9aea 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SerializedQueryTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SerializedQueryTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.25
 
-using System;
 using System.IO;
 using NUnit.Framework;
 using Xtensive.Core;
@@ -14,7 +13,6 @@
 using Xtensive.Orm.Serialization;
 using Xtensive.Orm.Tests.ObjectModel;
 using Xtensive.Orm.Tests.ObjectModel.ChinookDO;
-using System.Linq;
 using Xtensive.Orm.Providers;
 
 namespace Xtensive.Orm.Tests.Storage
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SessionDeactivationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SessionDeactivationTest.cs
index 952c6592b5..2648908d71 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SessionDeactivationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SessionDeactivationTest.cs
@@ -4,12 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Storage.SessionDeactivationTest
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SessionEventsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SessionEventsTest.cs
index ab4d3837bb..b4782c99f6 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SessionEventsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SessionEventsTest.cs
@@ -4,13 +4,10 @@
 // Created by: Alex Kofman
 // Created:    2009.10.08
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.SessionEventsTestModel;
-using System.Threading.Tasks;
-using System.Linq;
 
 namespace Xtensive.Orm.Tests.Storage.SessionEventsTestModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SessionSaveChangesPerformanceTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SessionSaveChangesPerformanceTest.cs
index 9f3c9de464..dcb7a29c37 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SessionSaveChangesPerformanceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SessionSaveChangesPerformanceTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2012.07.25
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.SessionSaveChangesPerformanceTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SetFieldTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SetFieldTest.cs
index ce0ddb0234..0f83d2a5de 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SetFieldTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SetFieldTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SingleTableTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SingleTableTest.cs
index fda1797ab2..cf4e01406c 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SingleTableTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SingleTableTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.10.01
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/SkippingValidationOnCommitTest.cs b/Orm/Xtensive.Orm.Tests/Storage/SkippingValidationOnCommitTest.cs
index 5b5b7ab428..51e7ae86bd 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/SkippingValidationOnCommitTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/SkippingValidationOnCommitTest.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/StructureReferencesAnEntityTest.cs b/Orm/Xtensive.Orm.Tests/Storage/StructureReferencesAnEntityTest.cs
index ee1331db58..7b7e03b466 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/StructureReferencesAnEntityTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/StructureReferencesAnEntityTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.02.16
 
-using System;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/StructureTest.cs b/Orm/Xtensive.Orm.Tests/Storage/StructureTest.cs
index 01d97ad1a5..0c20dd539b 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/StructureTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/StructureTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2008.05.28
 
-using System;
 using NUnit.Framework;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TemporaryTablePopulationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/TemporaryTablePopulationTest.cs
index af816cfea6..ca44509552 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TemporaryTablePopulationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TemporaryTablePopulationTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TransactionModesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/TransactionModesTest.cs
index bf2d8bad76..f5aa1ef0b9 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TransactionModesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TransactionModesTest.cs
@@ -5,7 +5,6 @@
 // Created:    2009.07.30
 
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.ObjectModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TransactionScopeIntegration.cs b/Orm/Xtensive.Orm.Tests/Storage/TransactionScopeIntegration.cs
index 34986564eb..4f0e653515 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TransactionScopeIntegration.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TransactionScopeIntegration.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.05.12
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.TransactionScopeIntegrationTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TransactionsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/TransactionsTest.cs
index 38b7aa5fe6..286bf01794 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TransactionsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TransactionsTest.cs
@@ -5,7 +5,6 @@
 // Created:    2008.08.27
 
 using NUnit.Framework;
-using System;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TypeCompatibilityTest.cs b/Orm/Xtensive.Orm.Tests/Storage/TypeCompatibilityTest.cs
index a5fc844b8c..950cca6411 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TypeCompatibilityTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TypeCompatibilityTest.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.19
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TypeDiscriminatorFromInterfaceTest.cs b/Orm/Xtensive.Orm.Tests/Storage/TypeDiscriminatorFromInterfaceTest.cs
index 35d18bfd43..dc95aaec3e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TypeDiscriminatorFromInterfaceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TypeDiscriminatorFromInterfaceTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.11.15
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.AdvancedDefaultAndTypeDiscriminatorTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/TypeIdAsParameterTest.cs b/Orm/Xtensive.Orm.Tests/Storage/TypeIdAsParameterTest.cs
index 950440dee9..c17d2ced53 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/TypeIdAsParameterTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/TypeIdAsParameterTest.cs
@@ -1,11 +1,7 @@
-using System;
 using System.Collections;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.TypeIdAsParameterTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/UnexpectedBehaviorTest.cs b/Orm/Xtensive.Orm.Tests/Storage/UnexpectedBehaviorTest.cs
index 1e7440f1b8..29dac30f8e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/UnexpectedBehaviorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/UnexpectedBehaviorTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.11
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.UnexpectedBehaviorTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/UpdateVersionTest.cs b/Orm/Xtensive.Orm.Tests/Storage/UpdateVersionTest.cs
index 52f1e8e4cb..a29a56b9a5 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/UpdateVersionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/UpdateVersionTest.cs
@@ -4,12 +4,10 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.06
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 using M=Xtensive.Orm.Model;
 
 #region Model
diff --git a/Orm/Xtensive.Orm.Tests/Storage/UpgradeModesTest.cs b/Orm/Xtensive.Orm.Tests/Storage/UpgradeModesTest.cs
index a03ed7a911..f6db74cd5e 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/UpgradeModesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/UpgradeModesTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.06.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidateEntityVersionsOnPersistTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidateEntityVersionsOnPersistTest.cs
index 6e883e9af2..3c725010e5 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidateEntityVersionsOnPersistTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidateEntityVersionsOnPersistTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.04.22
 
-using System.Linq;
 using NUnit.Framework;
 using ValidateEntityVersionsOnPersistTestModel;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidateOnlyModifiedFieldsTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidateOnlyModifiedFieldsTest.cs
index 487b9fa02c..20d6445c86 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidateOnlyModifiedFieldsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidateOnlyModifiedFieldsTest.cs
@@ -4,8 +4,6 @@
 // Created by: Julian Mamokin
 // Created:    2017.08.18
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Validation;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidationConstraintsOnGenericTypeTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidationConstraintsOnGenericTypeTest.cs
index 87ad888cc9..e9ef793691 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidationConstraintsOnGenericTypeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidationConstraintsOnGenericTypeTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.19
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidationContextClientProfileTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidationContextClientProfileTest.cs
index 7f60a5faf4..bf4a71aa19 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidationContextClientProfileTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidationContextClientProfileTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.25
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ValidationContextClientProfileModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidationContextTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidationContextTest.cs
index 22a95b71dd..48b6164958 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidationContextTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidationContextTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.09.15
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Validation;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidationOnDemandTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidationOnDemandTest.cs
index 611d2109d7..75754d1486 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidationOnDemandTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidationOnDemandTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.09.30
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Validation;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidationReferentialTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidationReferentialTest.cs
index 702a33a822..32c7b635f1 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidationReferentialTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidationReferentialTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.06.08
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.ValidationReferentialTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/ValidationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/ValidationTest.cs
index 9c35583101..2a52d12c14 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/ValidationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/ValidationTest.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Kofman
 // Created:    2008.08.31
 
-using System;
-using System.Linq;
 using System.Reflection;
-using System.Threading;
 using NUnit.Framework;
 using Xtensive.Orm.Validation;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/VersionBehaviorTest.cs b/Orm/Xtensive.Orm.Tests/Storage/VersionBehaviorTest.cs
index 3b3cf95b19..1111178767 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/VersionBehaviorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/VersionBehaviorTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.05
 
-using System;
-using System.Linq;
 using System.Diagnostics;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/VersionRootTests.cs b/Orm/Xtensive.Orm.Tests/Storage/VersionRootTests.cs
index 9ce899b0b6..2d4294becb 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/VersionRootTests.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/VersionRootTests.cs
@@ -4,13 +4,10 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.06
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 using Xtensive.Collections;
 
 #region Model
diff --git a/Orm/Xtensive.Orm.Tests/Storage/VersionValidationTest.cs b/Orm/Xtensive.Orm.Tests/Storage/VersionValidationTest.cs
index 1e23d2580a..72597f6e69 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/VersionValidationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/VersionValidationTest.cs
@@ -4,12 +4,10 @@
 // Created by: Ivan Galkin
 // Created:    2009.11.11
 
-using System;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Orm.Configuration;
-using System.Linq;
 //using Xtensive.Orm.Disconnected;
 
 #region Model
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntitySetOnwerVersionChangeTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntitySetOnwerVersionChangeTest.cs
index 96a66ef912..3f0cfb11ea 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntitySetOnwerVersionChangeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntitySetOnwerVersionChangeTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.03.02
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.VersioningConventionTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntityVersioningPolicyTest.cs b/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntityVersioningPolicyTest.cs
index 16a46323b0..2103254207 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntityVersioningPolicyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Versioning/EntityVersioningPolicyTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.03.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Storage.VersioningConventionTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Storage/Versioning/Model.cs b/Orm/Xtensive.Orm.Tests/Storage/Versioning/Model.cs
index 797cfb111d..593c9569bb 100644
--- a/Orm/Xtensive.Orm.Tests/Storage/Versioning/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Storage/Versioning/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.03.02
 
-using System;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.Storage.VersioningConventionTestModel
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/BuildOnEmptySchemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/BuildOnEmptySchemaTest.cs
index b9be26a0d6..250e34e18b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/BuildOnEmptySchemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/BuildOnEmptySchemaTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.09
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ChangeColumnCaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ChangeColumnCaseTest.cs
index ea52ae09c6..03d49d6b9d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ChangeColumnCaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ChangeColumnCaseTest.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.11.15
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ChangeFulltextCatalogTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ChangeFulltextCatalogTest.cs
index 90d3ed06d3..d55051cb28 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ChangeFulltextCatalogTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ChangeFulltextCatalogTest.cs
@@ -10,7 +10,6 @@
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Orm.Tests.Upgrade.ChangeFulltextCatalogTestModel;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade.ChangeFulltextCatalogTestModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ChangeNamespaceTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ChangeNamespaceTest.cs
index f3bc765b07..ab069e3b97 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ChangeNamespaceTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ChangeNamespaceTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.04.08
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.ChangeNamespaceTestModel;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ColumnTypeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ColumnTypeTest.cs
index afc20cddee..ee73f361f7 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ColumnTypeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ColumnTypeTest.cs
@@ -4,10 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ColumnTypeChangeInNewHierarchy.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ColumnTypeChangeInNewHierarchy.cs
index 5df1d3a740..0af3e167db 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ColumnTypeChangeInNewHierarchy.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ColumnTypeChangeInNewHierarchy.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplexTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplexTest.cs
index a8523e309b..77a071a9ff 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplexTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplexTest.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplextTestModel.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplextTestModel.cs
index 8b7cccac2a..e64e8ed427 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplextTestModel.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ComplextTestModel.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Orm.Building;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureNoGeneratorTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureNoGeneratorTest.cs
index 446f2beed7..d6f085f42b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureNoGeneratorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureNoGeneratorTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureWithGeneratorTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureWithGeneratorTest.cs
index 5ab5be2af8..15de5dcab3 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureWithGeneratorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/ExactTableStructureWithGeneratorTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/NewColumnInNewHierarchyTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/NewColumnInNewHierarchyTest.cs
index ee6758f8ba..15362061dc 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/NewColumnInNewHierarchyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/NewColumnInNewHierarchyTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedNoGeneratorTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedNoGeneratorTest.cs
index acac8aaecd..17d656475c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedNoGeneratorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedNoGeneratorTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedWithGeneratorTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedWithGeneratorTest.cs
index cd6ae93a9a..aaa6599f8c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedWithGeneratorTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/PrimaryKeyNameChangedWithGeneratorTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RemovedColumnInNewHierarchyTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RemovedColumnInNewHierarchyTest.cs
index 64e8f7973c..425e4f7ea8 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RemovedColumnInNewHierarchyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RemovedColumnInNewHierarchyTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RenamedColumnInNewHierarchyTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RenamedColumnInNewHierarchyTest.cs
index b56d15edf0..ff71a57ece 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RenamedColumnInNewHierarchyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/RenamedColumnInNewHierarchyTest.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/TestBase.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/TestBase.cs
index f5744c280e..85d9058345 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/TestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ConflictsByTable/TestBase.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/CustomTypeIdMap/CustomTypeIdMap.cs b/Orm/Xtensive.Orm.Tests/Upgrade/CustomTypeIdMap/CustomTypeIdMap.cs
index fd68d5d6da..84516a2e4a 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/CustomTypeIdMap/CustomTypeIdMap.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/CustomTypeIdMap/CustomTypeIdMap.cs
@@ -5,10 +5,7 @@
 // Created:    2014.07.18
 
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/DataUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/DataUpgradeTest.cs
index a44067244b..06f40b23cd 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/DataUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/DataUpgradeTest.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.30
 
-using System;
-using System.Linq;
 using System.Reflection;
-using System.Threading.Tasks;
 using NUnit.Framework;
 
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model1.cs
index f7809e3a71..39462249de 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.30
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.DataUpgrade.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model2.cs
index d23219fd0d..648f79d280 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Model2.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.30
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.DataUpgrade.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Upgrader.cs
index b40214ac78..f69f696a5c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DataUpgrade/Upgrader.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeDataConversions.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeDataConversions.cs
index f55f0202b0..c36d883bf8 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeDataConversions.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeDataConversions.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeOffsetUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeOffsetUpgradeTest.cs
index b98133eaa6..f3e0dace82 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeOffsetUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DateTimeOffsetUpgradeTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Groznov
 // Created:    2016.08.31
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DisableAutoResolveNamespaceConflictsTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DisableAutoResolveNamespaceConflictsTest.cs
index ac33a96108..63f2d2c41f 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DisableAutoResolveNamespaceConflictsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DisableAutoResolveNamespaceConflictsTest.cs
@@ -4,11 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2014.05.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeSimpleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeSimpleTest.cs
index 8c1b372371..31a17ce24a 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeSimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeSimpleTest.cs
@@ -4,10 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.15
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
-using System.Threading.Tasks;
 using NUnit.Framework;
 
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeTest.cs
index f59672238d..ef59170889 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/DomainUpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using System.Reflection;
 
@@ -38,7 +36,6 @@
 using StructureContainer2 = Xtensive.Orm.Tests.Upgrade.Model.Version2.StructureContainer2;
 using StructureContainer3 = Xtensive.Orm.Tests.Upgrade.Model.Version2.StructureContainer3;
 using StructureContainer4 = Xtensive.Orm.Tests.Upgrade.Model.Version2.StructureContainer4;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion1.cs
index 09acea8a8c..d07451b452 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.EntitySetUpgradeTest.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion2.cs
index 1f7778977b..bd6f5c247e 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.EntitySetUpgradeTest.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/UpgradeTest.cs
index b880d09f1d..7bb2c30811 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/UpgradeTest.cs
@@ -4,15 +4,12 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Tests.Upgrade.EntitySetUpgradeTest.Model.Version1;
 using M1 = Xtensive.Orm.Tests.Upgrade.EntitySetUpgradeTest.Model.Version1;
 using M2 = Xtensive.Orm.Tests.Upgrade.EntitySetUpgradeTest.Model.Version2;
 using NUnit.Framework;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade.EntitySetUpgradeTest
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/Upgrader.cs
index b40ed0b66e..e49a7a71f2 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/EntitySetUpgrade/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ExtractSuperClassTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ExtractSuperClassTest.cs
index b49bbfe99d..ad86167494 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ExtractSuperClassTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ExtractSuperClassTest.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ChangeTrackingModeComparisonTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ChangeTrackingModeComparisonTest.cs
index b79ab61b64..39e23adcd0 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ChangeTrackingModeComparisonTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ChangeTrackingModeComparisonTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.07.17
 
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Tests.Upgrade.FullText.Model.Version2;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ConvertionToStorageModelTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ConvertionToStorageModelTest.cs
index 08a213bd09..aa71728daa 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ConvertionToStorageModelTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/ConvertionToStorageModelTest.cs
@@ -4,13 +4,11 @@
 // Created by: Alexey Kulakov
 // Created:    2017.07.17
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Orm.Upgrade.Model;
 using Xtensive.Orm.Tests.Upgrade.FullText.ConversionToStorageModelModel;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade.FullText.ConversionToStorageModelModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTestTest.Models.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTestTest.Models.cs
index ad6155c024..6b27efe59e 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTestTest.Models.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTestTest.Models.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.21
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTextTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTextTest.cs
index 6ffab3439a..596b6b7cb6 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTextTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DomainUpgradeFullTextTest.cs
@@ -4,10 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.21
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
-using System.Threading.Tasks;
 using NUnit.Framework;
 
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DynamicFullTextCatalogTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DynamicFullTextCatalogTest.cs
index cc4e5bf8c6..92945ef9bc 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DynamicFullTextCatalogTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/DynamicFullTextCatalogTest.cs
@@ -13,7 +13,6 @@
 using Xtensive.Orm.Upgrade.Model;
 using Database1 = Xtensive.Orm.Tests.Upgrade.DynamicFulltextCatalogTestModel.Database1;
 using Database2 = Xtensive.Orm.Tests.Upgrade.DynamicFulltextCatalogTestModel.Database2;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade.DynamicFulltextCatalogTestModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextCatalogNameBuilderRegistrationTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextCatalogNameBuilderRegistrationTest.cs
index cdad2d963c..a2d3f709c4 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextCatalogNameBuilderRegistrationTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextCatalogNameBuilderRegistrationTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.07.12
 
-using System;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextDataTypeColumnUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextDataTypeColumnUpgradeTest.cs
index 22fc247d74..fd36880388 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextDataTypeColumnUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/FullText/FullTextDataTypeColumnUpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.11.14
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Definitions;
@@ -21,7 +19,6 @@
 using wrongModel2 = Xtensive.Orm.Tests.Upgrade.FullTextDataTypeColumnUpgrageTestModel7;
 using wrongModel3 = Xtensive.Orm.Tests.Upgrade.FullTextDataTypeColumnUpgrageTestModel8;
 using wrongModel4 = Xtensive.Orm.Tests.Upgrade.FullTextDataTypeColumnUpgrageTestModel9;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade.FullTextDataTypeColumnUpgrageTestModel1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/Model.cs
index a2ecfd5085..f437c39a42 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/Model.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.12.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm.Tests.Upgrade.GeneratorUpgrade
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultidatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultidatabaseTest.cs
index c19a6372b1..ee2df4f286 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultidatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultidatabaseTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.12.10
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultischemaTest.cs
index 61b44ab7eb..8549b93749 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/MultischemaTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.12.10
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/SimpleSchemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/SimpleSchemaTest.cs
index 5ba0ec6c0b..3a4338ebf3 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/SimpleSchemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/GeneratorUpgrade/SimpleSchemaTest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.10.10
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/DatabasePerNodeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/DatabasePerNodeTest.cs
index bf2bd2bed0..cbaa336a5c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/DatabasePerNodeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/DatabasePerNodeTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.19
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.RegularModel;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/HugeModelUpgradeTestBase.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/HugeModelUpgradeTestBase.cs
index 1ccc04ae54..9eac7def20 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/HugeModelUpgradeTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/HugeModelUpgradeTestBase.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/MappedTypesNodesTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/MappedTypesNodesTest.cs
index f6f5ae1a2a..261589943d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/MappedTypesNodesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/MappedTypesNodesTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.19
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.ModelWithMappings;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/ModelWithMappedTypes.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/ModelWithMappedTypes.cs
index 204c3fdcef..3a354f1796 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/ModelWithMappedTypes.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/ModelWithMappedTypes.cs
@@ -1,6 +1,4 @@
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.ModelWithMappings
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/RegularModel.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/RegularModel.cs
index 99b3df84ca..2f50af46f8 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/RegularModel.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/RegularModel.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.RegularModel
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/TwoPartsModel.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/TwoPartsModel.cs
index a401de53c9..73dddac2cd 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/TwoPartsModel.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/Models/TwoPartsModel.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.TwoPartsModel
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/PerformanceResultContainer.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/PerformanceResultContainer.cs
index a2cb1fefc7..b61514b398 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/PerformanceResultContainer.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/PerformanceResultContainer.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.19
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/SchemaPerNodeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/SchemaPerNodeTest.cs
index 01cf254120..ff6f4bd163 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/SchemaPerNodeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/SchemaPerNodeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.19
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.RegularModel;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoDatabasesPerNodeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoDatabasesPerNodeTest.cs
index 7f7374dc70..4769808a75 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoDatabasesPerNodeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoDatabasesPerNodeTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.19
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade.TwoPartsModel;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoSchemasPerNodeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoSchemasPerNodeTest.cs
index 1ee0c02c72..ddec4d7b36 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoSchemasPerNodeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/TwoSchemasPerNodeTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.24
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/UpgradePerformanceCounter.cs b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/UpgradePerformanceCounter.cs
index 3925f01770..e8629a5c74 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/UpgradePerformanceCounter.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/HugeModelUpgrade/UpgradePerformanceCounter.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.19
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Upgrade;
 
 namespace Xtensive.Orm.Tests.Upgrade.HugeModelUpgrade
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/IgnoreHintsTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/IgnoreHintsTest.cs
index e413ecd57f..ce14c46df2 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/IgnoreHintsTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/IgnoreHintsTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.19
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Core;
 
@@ -14,7 +12,6 @@
 using Xtensive.Orm.Tests.Upgrade.IgnoreHints.Model;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Orm.Building;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/KeyGeneratorTableCleanUpTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/KeyGeneratorTableCleanUpTest.cs
index 0b0f7ebe2d..6e194f9d5b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/KeyGeneratorTableCleanUpTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/KeyGeneratorTableCleanUpTest.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.09.28
 
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/LegacyUpgrade/LegacyUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/LegacyUpgrade/LegacyUpgradeTest.cs
index 71d1705bba..50c6b3b806 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/LegacyUpgrade/LegacyUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/LegacyUpgrade/LegacyUpgradeTest.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.11.20
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Tests;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ConvertDomainModelTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ConvertDomainModelTest.cs
index 805bffd65d..970ac60568 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ConvertDomainModelTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ConvertDomainModelTest.cs
@@ -4,9 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System.Linq;
 using NUnit.Framework;
-using System;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ForeignKeysTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ForeignKeysTest.cs
index 47913985ae..d54afaa070 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ForeignKeysTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ModelConversion/ForeignKeysTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.08.11
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion1.cs
index 766f896d7e..4e33c5071e 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion2.cs
index f5daea329e..4a4ed8a5a5 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion2.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Tests.Upgrade.Model.Version2
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion3.cs b/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion3.cs
index 69d0e56ce3..867b30f645 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion3.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/ModelVersion3.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Model.Version3
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/Model.cs
index 442542e8da..043d42e1b5 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.24
 
-using System;
 using System.Linq.Expressions;
 using System.Security.Cryptography;
 using System.Text;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultidatabaseDomainTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultidatabaseDomainTest.cs
index 555e65627a..ae1fd2d3e9 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultidatabaseDomainTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultidatabaseDomainTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultischemaDomainTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultischemaDomainTest.cs
index 9864d2a375..2a973475e1 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultischemaDomainTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/MultischemaDomainTest.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SimpleDomainTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SimpleDomainTest.cs
index 31d06e16eb..50b3223b0d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SimpleDomainTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SimpleDomainTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.24
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Tests.Upgrade.NewSkip.Model.Users;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleDatabaseNodeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleDatabaseNodeTest.cs
index fb1b29c337..7a0482ee15 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleDatabaseNodeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleDatabaseNodeTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleSchemaNodeBuildingTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleSchemaNodeBuildingTest.cs
index 72ee68630a..756a468269 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleSchemaNodeBuildingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SingleSchemaNodeBuildingTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SkipBuildingTestBase.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SkipBuildingTestBase.cs
index 28218dc349..bc3e9a036d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SkipBuildingTestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewSkip/SkipBuildingTestBase.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.24
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NewUpgradeEventsAndPropertiesTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NewUpgradeEventsAndPropertiesTest.cs
index 97bc5e2386..733ad78173 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NewUpgradeEventsAndPropertiesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NewUpgradeEventsAndPropertiesTest.cs
@@ -4,11 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.09.28
 
-using System;
-using System.Collections.Generic;
 using System.Data;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Upgrade.NewUpgradeEventsAndPropertiesTestModel;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NodeBasedExtractedModelBuilderTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NodeBasedExtractedModelBuilderTest.cs
index d39806300d..32460b9c7e 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NodeBasedExtractedModelBuilderTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NodeBasedExtractedModelBuilderTest.cs
@@ -5,7 +5,6 @@
 // Created:    2016.12.13
 
 using System.Text;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/NonNullableReferenceRemovalTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/NonNullableReferenceRemovalTest.cs
index b5c7d0ec23..421c18223f 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/NonNullableReferenceRemovalTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/NonNullableReferenceRemovalTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.08.20
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 using Model1 = Xtensive.Orm.Tests.Upgrade.NonNullableReferenceRemovalTestModel.Model1;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/PerformSafelyFromEmptyDatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/PerformSafelyFromEmptyDatabaseTest.cs
index 48023981ed..58463f9125 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/PerformSafelyFromEmptyDatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/PerformSafelyFromEmptyDatabaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.07.05
 
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion1.cs
index dddad28ee0..86b1b3bd08 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.27
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version1
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2Perform.cs b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2Perform.cs
index c6b9046e0e..f1b549bb38 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2Perform.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2Perform.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.27
 
-using System;
 using System.Diagnostics;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2PerformSafely.cs b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2PerformSafely.cs
index c8f288c657..55aca267d9 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2PerformSafely.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyModelVersion2PerformSafely.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.27
 
-using System;
 using System.Diagnostics;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyUpgradeTest.cs
index cb3d0336f7..7d19ecb4b5 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/PrimaryKeyUpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.27
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Collections;
@@ -14,12 +12,10 @@
 using Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version1;
 using Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version2PerformSafely;
 using Xtensive.Orm.Upgrade;
-using System.Linq;
 using Author = Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version1.Author;
 using Book = Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version1.Book;
 using Author2 = Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version2PerformSafely.Author;
 using Book2 = Xtensive.Orm.Tests.Upgrade.PrimaryKeyModel.Version2PerformSafely.Book;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion1.cs
index 40ff1eff73..8cafdaff85 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Recycled.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion2.cs
index 0757b9824a..810955b998 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/ModelVersion2.cs
@@ -5,7 +5,6 @@
 // Created:    2009.05.20
 
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Recycled.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/RecycledUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/RecycledUpgradeTest.cs
index 569e568602..c9d6eab88b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/RecycledUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/RecycledUpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using System.Reflection;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/Upgrader.cs
index 646144f88d..6157030ef8 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Recycled/Upgrader.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/RecycledDefinitionTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/RecycledDefinitionTest.cs
index a9cb8d69d6..3811d2747b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/RecycledDefinitionTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/RecycledDefinitionTest.cs
@@ -4,10 +4,6 @@
 // Created by: Andrey Turkov
 // Created:    2013.08.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Tests.Upgrade.RecycledDefinitionTestModel;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/RemoveColumnWithRenameTableTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/RemoveColumnWithRenameTableTest.cs
index 2eaf60d9f8..0f198ad98a 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/RemoveColumnWithRenameTableTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/RemoveColumnWithRenameTableTest.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.07.05
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 using V1=Xtensive.Orm.Tests.Upgrade.RemoveColumnWithRenameTableTestModel.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion1.cs
index 211931355e..9a9d9db656 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Sample3.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion2.cs
index 669b20d07e..599c982a6c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/ModelVersion2.cs
@@ -5,11 +5,9 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Sample3.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Sample3UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Sample3UpgradeTest.cs
index feca61c76a..0128c5a277 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Sample3UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Sample3UpgradeTest.cs
@@ -5,7 +5,6 @@
 // Created:    2009.05.20
 
 using System.Collections;
-using System.Linq;
 using NUnit.Framework;
 using System.Reflection;
 using Xtensive.Collections;
@@ -14,7 +13,6 @@
 using Xtensive.Orm.Tests.Upgrade.Sample3.Model.Version2;
 using M1 = Xtensive.Orm.Tests.Upgrade.Sample3.Model.Version1;
 using M2 = Xtensive.Orm.Tests.Upgrade.Sample3.Model.Version2;
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.Sample3
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Upgrader.cs
index ab7f92693d..9242778a5b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Sample3/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MakingSchemaExtractionResultSharedTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MakingSchemaExtractionResultSharedTest.cs
index 5d1e94f53f..bf57df305d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MakingSchemaExtractionResultSharedTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MakingSchemaExtractionResultSharedTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.02
 
-using System;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MappingResolverTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MappingResolverTest.cs
index c897c2b2dd..50e452c342 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MappingResolverTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MappingResolverTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.02
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/Model.cs
index 75cb47bef5..f715d76bd8 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/Model.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.03
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultidatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultidatabaseTest.cs
index 9e476e104e..0e69fc4586 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultidatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultidatabaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.03
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.MetadataUpdate.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultischemaTest.cs
index e61dfde09c..214c69b844 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/MultischemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.03
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.MetadataUpdate.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/SimpleTest.cs
index e70e94b150..858c08d62c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/MetadataUpdate/SimpleTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.04.03
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.MetadataUpdate.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Model.cs
index 0b8eb5d262..7fbafc8e88 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.02
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.SchemaSharing.Model
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/Model.cs
index 10e7e776cb..b27557b077 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/Model.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultidatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultidatabaseTest.cs
index 0a301578ad..7794c79d56 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultidatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultidatabaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.30
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultischemaTest.cs
index 9a874257e4..b163060eb6 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/MultischemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.30
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/SimpleTest.cs
index 17c86aefb8..546bcd4f7b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/QueryBuilder/SimpleTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.30
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.QueryBuilder.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/Model.cs
index 9885b40f5c..ceed58852a 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.29
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultidatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultidatabaseTest.cs
index 6a94db6b80..2c049a242a 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultidatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultidatabaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.29
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.Requests.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultischemaTest.cs
index e8f589d06b..bc9538a0cc 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/MultischemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.29
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/SimpleTest.cs
index 4dd8ce0249..01898eede3 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/Requests/SimpleTest.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.29
 
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using model= Xtensive.Orm.Tests.Upgrade.SchemaSharing.Requests.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/Model.cs
index 01f54371af..1924daf575 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/Model.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.28
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultidatabaseTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultidatabaseTest.cs
index 082d6be2ad..220a672cbd 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultidatabaseTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultidatabaseTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.28
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.SqlExecutor.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultischemaTest.cs
index b79cec09d9..a62d4efa1c 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/MultischemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.28
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.SqlExecutor.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/SimpleTest.cs
index 4a0a36a2af..e482c6c635 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/SqlExecutor/SimpleTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.SqlExecutor.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/StorageNodeBuildingTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/StorageNodeBuildingTest.cs
index b0ac8be297..b9cdf01d7e 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/StorageNodeBuildingTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/StorageNodeBuildingTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.03
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/MultischemaTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/MultischemaTest.cs
index f185934f3a..236655a020 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/MultischemaTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/MultischemaTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.03
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.TemporaryTableManager.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/SimpleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/SimpleTest.cs
index c24d28449b..f9e7f315db 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/SimpleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SchemaSharing/TemporaryTableManager/SimpleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2017.03.03
 
-using System.Collections.Generic;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using model = Xtensive.Orm.Tests.Upgrade.SchemaSharing.TemporaryTableManager.Model;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion1.cs
index 681cb5cfb8..ffd9e8909d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.15
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.Upgrade.Model.SimpleVersion1
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion2.cs
index 43c6ff6337..6e9d3a01e7 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SimpleModelVersion2.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.15
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.Upgrade.Model.SimpleVersion2
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SimpleUpgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SimpleUpgrader.cs
index 9cd472ab48..096e7f82f7 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SimpleUpgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SimpleUpgrader.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.15
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 using Xtensive.Orm.Tests.Upgrade.Model.SimpleVersion2;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SkipUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SkipUpgradeTest.cs
index 0653f68c8d..d0cbc5e78b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SkipUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SkipUpgradeTest.cs
@@ -4,12 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.03.05
 
-using System;
-using System.Collections.Generic;
 using NUnit.Framework;
-using System.Linq;
 using Xtensive.Orm.Tests.Upgrade.SkipUpgradeTestModel;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Tests.Upgrade.SkipUpgradeTestModel
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SplitHierarchyTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SplitHierarchyTest.cs
index d7f66ab832..c21047ab5d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SplitHierarchyTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SplitHierarchyTest.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.09.19
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/SqlWorkerAndSqlAsyncWorkerTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/SqlWorkerAndSqlAsyncWorkerTest.cs
index 54f776c982..565f0c0231 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/SqlWorkerAndSqlAsyncWorkerTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/SqlWorkerAndSqlAsyncWorkerTest.cs
@@ -4,12 +4,7 @@
 // Created by: Julian Mamokin
 // Created:    2017.03.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeConversionVerifierTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeConversionVerifierTest.cs
index e5cb08fb12..b4a43196a8 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeConversionVerifierTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeConversionVerifierTest.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Upgrade.Model;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdPreserveTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdPreserveTest.cs
index b045663fef..bbe4babacc 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdPreserveTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdPreserveTest.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.01
 
-using System;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Many2SingleClassTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Many2SingleClassTest.cs
index d7fbdf5c7a..3068445e14 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Many2SingleClassTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Many2SingleClassTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.29
 
-using System.Linq;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Upgrade.TypeIdUpgrade
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Model.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Model.cs
index e191a5cc29..140b621e67 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Model.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Model.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.28
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Tests.Upgrade.TypeIdUpgrade.Model
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Single2ManyClassesTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Single2ManyClassesTest.cs
index 82b57315c6..df1029e653 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Single2ManyClassesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Single2ManyClassesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.28
 
-using System.Linq;
 using NUnit.Framework;
 
 namespace Xtensive.Orm.Tests.Upgrade.TypeIdUpgrade
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Upgrader.cs
index ed727dd18e..2630b5a928 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/Upgrader.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.29
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/VersionUpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/VersionUpgradeTest.cs
index fd8b40807b..47e33e11ba 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/VersionUpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/TypeIdUpgrade/VersionUpgradeTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.29
 
-using System.Linq;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion1.cs
index ca165f974c..3a703b262b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRules.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion2.cs
index 7b748f3204..c86a5d6027 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/ModelVersion2.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRules.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/UpgradeTest.cs
index 62f13f6c01..86b8e9d578 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/Upgrader.cs
index fba35f6759..4e491507d1 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRules/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsAndHyphensRule.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsAndHyphensRule.cs
index b9c91e2d99..b43a3abfa7 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsAndHyphensRule.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsAndHyphensRule.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsRuleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsRuleTest.cs
index 22c6c37921..763184ec84 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsRuleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveDotsRuleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveHyphensRuleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveHyphensRuleTest.cs
index 472e75b5b8..1b7f3d19ed 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveHyphensRuleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/RemoveHyphensRuleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/SynonymsOfNamespacesTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/SynonymsOfNamespacesTest.cs
index 915166d9f7..3fa5d2f2f5 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/SynonymsOfNamespacesTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/SynonymsOfNamespacesTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TargetModels.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TargetModels.cs
index be31b38a28..d958bb9e5f 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TargetModels.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TargetModels.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.03
 
-using System.Collections.Generic;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Upgrade;
 
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TestBase.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TestBase.cs
index d12c2cbd0b..54c3cc7399 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TestBase.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/TestBase.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.03
 
-using System;
-using System.Linq;
 using System.Reflection;
 using NUnit.Framework;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsAndHyphensRule.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsAndHyphensRule.cs
index 4152b0a64b..253ce6d14e 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsAndHyphensRule.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsAndHyphensRule.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsRuleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsRuleTest.cs
index 4c10c64b6c..bb02bf60c6 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsRuleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreDotsRuleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreHyphensRuleTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreHyphensRuleTest.cs
index db10281753..c920d271f2 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreHyphensRuleTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeAndNamingRulesAdvanced/UnderscoreHyphensRuleTest.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeAndNamingRulesAdvanced
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeContextTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeContextTest.cs
index b31f0f00c9..534702e91f 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeContextTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeContextTest.cs
@@ -4,12 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2018.09.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeDateTimeOffsetTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeDateTimeOffsetTest.cs
index 50b2ba78c2..2d7aa9dcd1 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeDateTimeOffsetTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeDateTimeOffsetTest.cs
@@ -4,10 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.02.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeSchemaWithNonDOSequences.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeSchemaWithNonDOSequences.cs
index 7e9bbcb67c..7ad85c5396 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeSchemaWithNonDOSequences.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeSchemaWithNonDOSequences.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Services;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeTestTemplate.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeTestTemplate.cs
index ba256e062e..dbd1eefd59 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeTestTemplate.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeTestTemplate.cs
@@ -4,9 +4,6 @@
 // Created by: <AUTHOR>
 // Created:    <YYYY.MM.DD>
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion1.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion1.cs
index ae8ea5a4d7..da9aa8ff0b 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion1.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion1.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeToStructure.Model.Version1
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion2.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion2.cs
index 54207118b2..d2b9257327 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion2.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/ModelVersion2.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Tests.Upgrade.UpgradeToStructure.Model.Version2
 {
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/UpgradeTest.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/UpgradeTest.cs
index 09f8d7c12d..dea968dce0 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/UpgradeTest.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/UpgradeTest.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using M1 = Xtensive.Orm.Tests.Upgrade.UpgradeToStructure.Model.Version1;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/Upgrader.cs
index 965e849cef..906eb0a096 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/UpgradeToStructure/Upgrader.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm.Tests/Upgrade/Upgrader.cs b/Orm/Xtensive.Orm.Tests/Upgrade/Upgrader.cs
index 55e7258d45..6aaf877c9d 100644
--- a/Orm/Xtensive.Orm.Tests/Upgrade/Upgrader.cs
+++ b/Orm/Xtensive.Orm.Tests/Upgrade/Upgrader.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 using Xtensive.Orm.Tests.Upgrade.Model.Version2;
diff --git a/Orm/Xtensive.Orm.Tests/_Manual/Validation/Person.cs b/Orm/Xtensive.Orm.Tests/_Manual/Validation/Person.cs
index 937d29ada9..e0923c13e2 100644
--- a/Orm/Xtensive.Orm.Tests/_Manual/Validation/Person.cs
+++ b/Orm/Xtensive.Orm.Tests/_Manual/Validation/Person.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.10.27
 
-using System;
 using Xtensive.Orm.Tests._Manual.Validation;
 using Xtensive.Orm.Validation;
 
diff --git a/Orm/Xtensive.Orm.Tests/_Manual/Validation/PhoneNumberConstraint.cs b/Orm/Xtensive.Orm.Tests/_Manual/Validation/PhoneNumberConstraint.cs
index affab2c779..65324bb5bd 100644
--- a/Orm/Xtensive.Orm.Tests/_Manual/Validation/PhoneNumberConstraint.cs
+++ b/Orm/Xtensive.Orm.Tests/_Manual/Validation/PhoneNumberConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.10.28
 
-using System;
 using System.Text.RegularExpressions;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Validation;
diff --git a/Orm/Xtensive.Orm.Tests/_Manual/Validation/TestFixture.cs b/Orm/Xtensive.Orm.Tests/_Manual/Validation/TestFixture.cs
index 0bb73d83e6..002534fdbe 100644
--- a/Orm/Xtensive.Orm.Tests/_Manual/Validation/TestFixture.cs
+++ b/Orm/Xtensive.Orm.Tests/_Manual/Validation/TestFixture.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.10.28
 
-using System;
 using NUnit.Framework;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Validation;
diff --git a/Orm/Xtensive.Orm/Annotations.cs b/Orm/Xtensive.Orm/Annotations.cs
index 234591ee70..af9a62f872 100644
--- a/Orm/Xtensive.Orm/Annotations.cs
+++ b/Orm/Xtensive.Orm/Annotations.cs
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-using System;
 
 // ReSharper disable CheckNamespace
 namespace JetBrains.Annotations
diff --git a/Orm/Xtensive.Orm/Arithmetic/Arithmetic.cs b/Orm/Xtensive.Orm/Arithmetic/Arithmetic.cs
index dae2b7b2b5..5b55b77e63 100644
--- a/Orm/Xtensive.Orm/Arithmetic/Arithmetic.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/Arithmetic.cs
@@ -4,10 +4,8 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.12
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
-using System.Threading;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Arithmetic/ArithmeticBase.cs b/Orm/Xtensive.Orm/Arithmetic/ArithmeticBase.cs
index 22819604ef..9ef3f27fcd 100644
--- a/Orm/Xtensive.Orm/Arithmetic/ArithmeticBase.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/ArithmeticBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.06
 
-using System;
 using System.Collections.Concurrent;
 using System.Diagnostics;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Arithmetic/ArithmeticProvider.cs b/Orm/Xtensive.Orm/Arithmetic/ArithmeticProvider.cs
index a862dff99b..780fe1b22a 100644
--- a/Orm/Xtensive.Orm/Arithmetic/ArithmeticProvider.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/ArithmeticProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.22
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Arithmetic/ArithmeticRules.cs b/Orm/Xtensive.Orm/Arithmetic/ArithmeticRules.cs
index 020f3759ca..85162ab6db 100644
--- a/Orm/Xtensive.Orm/Arithmetic/ArithmeticRules.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/ArithmeticRules.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.10
 
-using System;
 
 namespace Xtensive.Arithmetic
 {
diff --git a/Orm/Xtensive.Orm/Arithmetic/ArithmeticStruct.cs b/Orm/Xtensive.Orm/Arithmetic/ArithmeticStruct.cs
index c28d00273c..cc738a9cc5 100644
--- a/Orm/Xtensive.Orm/Arithmetic/ArithmeticStruct.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/ArithmeticStruct.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.12
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Arithmetic/Internal/NullableArithmetic.cs b/Orm/Xtensive.Orm/Arithmetic/Internal/NullableArithmetic.cs
index 7e7e93c837..18a9ff9407 100644
--- a/Orm/Xtensive.Orm/Arithmetic/Internal/NullableArithmetic.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/Internal/NullableArithmetic.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.06
 
-using System;
 
 
 namespace Xtensive.Arithmetic
diff --git a/Orm/Xtensive.Orm/Arithmetic/Internal/PrimitiveArithmetics.cs b/Orm/Xtensive.Orm/Arithmetic/Internal/PrimitiveArithmetics.cs
index e14f4c694f..5ed36d8ef9 100644
--- a/Orm/Xtensive.Orm/Arithmetic/Internal/PrimitiveArithmetics.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/Internal/PrimitiveArithmetics.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.22
 
-using System;
 using Xtensive.Arithmetic;
 
 
diff --git a/Orm/Xtensive.Orm/Arithmetic/NullBehavior.cs b/Orm/Xtensive.Orm/Arithmetic/NullBehavior.cs
index 95bd2f3549..4e46069a45 100644
--- a/Orm/Xtensive.Orm/Arithmetic/NullBehavior.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/NullBehavior.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.10
 
-using System;
 
 namespace Xtensive.Arithmetic
 {
diff --git a/Orm/Xtensive.Orm/Arithmetic/OverflowBehavior.cs b/Orm/Xtensive.Orm/Arithmetic/OverflowBehavior.cs
index 0b9aa67e3e..4ce10e7cda 100644
--- a/Orm/Xtensive.Orm/Arithmetic/OverflowBehavior.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/OverflowBehavior.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.10
 
-using System;
 
 namespace Xtensive.Arithmetic
 {
diff --git a/Orm/Xtensive.Orm/Arithmetic/WrappingArithmetic{T,TBase}.cs b/Orm/Xtensive.Orm/Arithmetic/WrappingArithmetic{T,TBase}.cs
index 3aee2b5199..41fd99d1d0 100644
--- a/Orm/Xtensive.Orm/Arithmetic/WrappingArithmetic{T,TBase}.cs
+++ b/Orm/Xtensive.Orm/Arithmetic/WrappingArithmetic{T,TBase}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.06
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Caching/CacheBase.cs b/Orm/Xtensive.Orm/Caching/CacheBase.cs
index bdcc5f7d4e..f99f658aa2 100755
--- a/Orm/Xtensive.Orm/Caching/CacheBase.cs
+++ b/Orm/Xtensive.Orm/Caching/CacheBase.cs
@@ -2,9 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Caching/FastConcurrentLruCache{TKey, TItem}.cs b/Orm/Xtensive.Orm/Caching/FastConcurrentLruCache{TKey, TItem}.cs
index 5fcd8e86b0..1be107b2ff 100755
--- a/Orm/Xtensive.Orm/Caching/FastConcurrentLruCache{TKey, TItem}.cs	
+++ b/Orm/Xtensive.Orm/Caching/FastConcurrentLruCache{TKey, TItem}.cs	
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using BitFaster.Caching.Lru;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Caching/InfiniteCache.cs b/Orm/Xtensive.Orm/Caching/InfiniteCache.cs
index d44904cf13..5aded84204 100644
--- a/Orm/Xtensive.Orm/Caching/InfiniteCache.cs
+++ b/Orm/Xtensive.Orm/Caching/InfiniteCache.cs
@@ -4,9 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.11
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Caching/Interfaces/ICache.cs b/Orm/Xtensive.Orm/Caching/Interfaces/ICache.cs
index d9aa76a80f..61d3e7cd73 100644
--- a/Orm/Xtensive.Orm/Caching/Interfaces/ICache.cs
+++ b/Orm/Xtensive.Orm/Caching/Interfaces/ICache.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2007.05.25
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem, TCached}.cs b/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem, TCached}.cs
index 4ab9bd12b5..a9519c0c65 100644
--- a/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem, TCached}.cs	
+++ b/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem, TCached}.cs	
@@ -4,9 +4,7 @@
 // Created by: Alex Ustinov
 // Created:    2007.05.28
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Conversion;
diff --git a/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem}.cs b/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem}.cs
index a0e06a916c..5b935ba36a 100644
--- a/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem}.cs	
+++ b/Orm/Xtensive.Orm/Caching/LruCache{TKey, TItem}.cs	
@@ -4,9 +4,7 @@
 // Created by: Alex Ustinov
 // Created:    2007.05.28
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Conversion;
diff --git a/Orm/Xtensive.Orm/Caching/MfLruCache.cs b/Orm/Xtensive.Orm/Caching/MfLruCache.cs
index c220da06f3..90b1d5a583 100644
--- a/Orm/Xtensive.Orm/Caching/MfLruCache.cs
+++ b/Orm/Xtensive.Orm/Caching/MfLruCache.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Ustinov
 // Created:    2007.05.28
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Caching/WeakCache.cs b/Orm/Xtensive.Orm/Caching/WeakCache.cs
index 0f4596956a..cf8b1b8035 100644
--- a/Orm/Xtensive.Orm/Caching/WeakCache.cs
+++ b/Orm/Xtensive.Orm/Caching/WeakCache.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Ustinov
 // Created:    2007.05.28
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Runtime.InteropServices;
 using System.Security;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Caching/WeakestCache.cs b/Orm/Xtensive.Orm/Caching/WeakestCache.cs
index f544c16498..cc0015f89b 100644
--- a/Orm/Xtensive.Orm/Caching/WeakestCache.cs
+++ b/Orm/Xtensive.Orm/Caching/WeakestCache.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Ustinov
 // Created:    2007.05.28
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Collections/BindingCollection.cs b/Orm/Xtensive.Orm/Collections/BindingCollection.cs
index de594dbe0e..e73d76b76f 100644
--- a/Orm/Xtensive.Orm/Collections/BindingCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/BindingCollection.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2009.03.12
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Collections/ChainedBuffer.cs b/Orm/Xtensive.Orm/Collections/ChainedBuffer.cs
index fffd5b3973..b08c8c959b 100644
--- a/Orm/Xtensive.Orm/Collections/ChainedBuffer.cs
+++ b/Orm/Xtensive.Orm/Collections/ChainedBuffer.cs
@@ -4,11 +4,8 @@
 // Created by: Alena Mikshina
 // Created:    2013.08.19
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
-using System.Linq;
 
 namespace Xtensive.Collections
 {
diff --git a/Orm/Xtensive.Orm/Collections/ChangeNotifierEventArgs.cs b/Orm/Xtensive.Orm/Collections/ChangeNotifierEventArgs.cs
index 43a2f109d1..f4a8a9cf9b 100644
--- a/Orm/Xtensive.Orm/Collections/ChangeNotifierEventArgs.cs
+++ b/Orm/Xtensive.Orm/Collections/ChangeNotifierEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.10.15
 
-using System;
 
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/ClassifiedCollection.cs b/Orm/Xtensive.Orm/Collections/ClassifiedCollection.cs
index 38688ca652..5774f4cafa 100644
--- a/Orm/Xtensive.Orm/Collections/ClassifiedCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/ClassifiedCollection.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.02
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 
 namespace Xtensive.Collections
 {
diff --git a/Orm/Xtensive.Orm/Collections/CollectionBaseSlim.cs b/Orm/Xtensive.Orm/Collections/CollectionBaseSlim.cs
index 46f2e5922a..845e90b343 100644
--- a/Orm/Xtensive.Orm/Collections/CollectionBaseSlim.cs
+++ b/Orm/Xtensive.Orm/Collections/CollectionBaseSlim.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2007.09.24
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Collections/CollectionUtils.cs b/Orm/Xtensive.Orm/Collections/CollectionUtils.cs
index aa47715dcc..8035a187d5 100644
--- a/Orm/Xtensive.Orm/Collections/CollectionUtils.cs
+++ b/Orm/Xtensive.Orm/Collections/CollectionUtils.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Kudelin
 // Created:    2019.03.21
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/Deque.cs b/Orm/Xtensive.Orm/Collections/Deque.cs
index 2de039b414..bf225df52e 100644
--- a/Orm/Xtensive.Orm/Collections/Deque.cs
+++ b/Orm/Xtensive.Orm/Collections/Deque.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Collections/DirectionCollection.cs b/Orm/Xtensive.Orm/Collections/DirectionCollection.cs
index 61117ee635..cf9108c222 100644
--- a/Orm/Xtensive.Orm/Collections/DirectionCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/DirectionCollection.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.09.24
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Conversion;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Collections/EnumerableUtils.cs b/Orm/Xtensive.Orm/Collections/EnumerableUtils.cs
index 86219ddf9e..81b7779d1e 100644
--- a/Orm/Xtensive.Orm/Collections/EnumerableUtils.cs
+++ b/Orm/Xtensive.Orm/Collections/EnumerableUtils.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.04
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/ExtensionCollection.cs b/Orm/Xtensive.Orm/Collections/ExtensionCollection.cs
index fe851865d1..d34c7cd4f2 100644
--- a/Orm/Xtensive.Orm/Collections/ExtensionCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/ExtensionCollection.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.03
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Collections/FixedList3.cs b/Orm/Xtensive.Orm/Collections/FixedList3.cs
index c7a0539ca3..d9c16fab74 100644
--- a/Orm/Xtensive.Orm/Collections/FixedList3.cs
+++ b/Orm/Xtensive.Orm/Collections/FixedList3.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.10.20
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Collections/FlagCollection.cs b/Orm/Xtensive.Orm/Collections/FlagCollection.cs
index 4c0948f4de..d8460780ca 100644
--- a/Orm/Xtensive.Orm/Collections/FlagCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/FlagCollection.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2007.10.01
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/Edge.cs b/Orm/Xtensive.Orm/Collections/Graphs/Edge.cs
index dea53bd5b6..73c3f65181 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/Edge.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/Edge.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/Edge{TValue}.cs b/Orm/Xtensive.Orm/Collections/Graphs/Edge{TValue}.cs
index 8016c23ef9..7d02aef2bd 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/Edge{TValue}.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/Edge{TValue}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System;
 
 
 namespace Xtensive.Collections.Graphs
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/Graph.cs b/Orm/Xtensive.Orm/Collections/Graphs/Graph.cs
index 4d476f797e..9b94243496 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/Graph.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/Graph.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/Node.cs b/Orm/Xtensive.Orm/Collections/Graphs/Node.cs
index f5fab8e383..3187d5197c 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/Node.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/Node.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Collections.Graphs
 {
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/Node{TValue}.cs b/Orm/Xtensive.Orm/Collections/Graphs/Node{TValue}.cs
index 95dcf1c502..ee3444ad68 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/Node{TValue}.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/Node{TValue}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System;
 
 
 namespace Xtensive.Collections.Graphs
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSortResult.cs b/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSortResult.cs
index 9dd39579b8..53765468ef 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSortResult.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSortResult.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System.Collections.Generic;
 
 namespace Xtensive.Collections.Graphs
 {
diff --git a/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSorter.cs b/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSorter.cs
index 2468332ca7..d669c16b5c 100644
--- a/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSorter.cs
+++ b/Orm/Xtensive.Orm/Collections/Graphs/TopologicalSorter.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2012.02.22
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Collections.Graphs
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/IChangeNotifier.cs b/Orm/Xtensive.Orm/Collections/Interfaces/IChangeNotifier.cs
index 01bd96f688..6bde7b925f 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/IChangeNotifier.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/IChangeNotifier.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.10.15
 
-using System;
 using Xtensive.Collections;
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/IClassifiedCollection.cs b/Orm/Xtensive.Orm/Collections/Interfaces/IClassifiedCollection.cs
index a6f7b7ccbe..8eb6e157ba 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/IClassifiedCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/IClassifiedCollection.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.02
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 
 
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/IDeque.cs b/Orm/Xtensive.Orm/Collections/Interfaces/IDeque.cs
index 324a6f1891..bfd9a5dec1 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/IDeque.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/IDeque.cs
@@ -4,9 +4,7 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.01.07
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 namespace Xtensive.Collections
 {
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/IExtensionCollection.cs b/Orm/Xtensive.Orm/Collections/Interfaces/IExtensionCollection.cs
index fc764da03a..4d7ff568bc 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/IExtensionCollection.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/IExtensionCollection.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.03
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Collections
 {
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/IFilterable.cs b/Orm/Xtensive.Orm/Collections/Interfaces/IFilterable.cs
index a7367f183c..35ae8bc960 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/IFilterable.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/IFilterable.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.11.13
 
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/IPriorityQueue.cs b/Orm/Xtensive.Orm/Collections/Interfaces/IPriorityQueue.cs
index f346f8ca73..debf38c6e9 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/IPriorityQueue.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/IPriorityQueue.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2007.06.13
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Collections/Interfaces/ITopDeque{K,V}.cs b/Orm/Xtensive.Orm/Collections/Interfaces/ITopDeque{K,V}.cs
index 23667c4be5..a52128284c 100644
--- a/Orm/Xtensive.Orm/Collections/Interfaces/ITopDeque{K,V}.cs
+++ b/Orm/Xtensive.Orm/Collections/Interfaces/ITopDeque{K,V}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.26
 
-using System.Collections.Generic;
 
 namespace Xtensive.Collections
 {
diff --git a/Orm/Xtensive.Orm/Collections/Internals/PriorityQueueItemComparer.cs b/Orm/Xtensive.Orm/Collections/Internals/PriorityQueueItemComparer.cs
index fef57ac3d3..df1cb45288 100644
--- a/Orm/Xtensive.Orm/Collections/Internals/PriorityQueueItemComparer.cs
+++ b/Orm/Xtensive.Orm/Collections/Internals/PriorityQueueItemComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Gamzov
 // Created:    2007.06.14
 
-using System.Collections.Generic;
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/NativeTypeClassifier.cs b/Orm/Xtensive.Orm/Collections/NativeTypeClassifier.cs
index f1828f7217..be77954701 100644
--- a/Orm/Xtensive.Orm/Collections/NativeTypeClassifier.cs
+++ b/Orm/Xtensive.Orm/Collections/NativeTypeClassifier.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.02
 
-using System;
-using System.Collections.Generic;
 
 using Xtensive.Reflection;
-using System.Linq;
 
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/ReadOnlyHashSet{T}.cs b/Orm/Xtensive.Orm/Collections/ReadOnlyHashSet{T}.cs
index c6181ff649..07a4e2471d 100644
--- a/Orm/Xtensive.Orm/Collections/ReadOnlyHashSet{T}.cs
+++ b/Orm/Xtensive.Orm/Collections/ReadOnlyHashSet{T}.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.14
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 namespace Xtensive.Collections
diff --git a/Orm/Xtensive.Orm/Collections/SinglyLinkedList.cs b/Orm/Xtensive.Orm/Collections/SinglyLinkedList.cs
index 6654ef48cd..f249650052 100644
--- a/Orm/Xtensive.Orm/Collections/SinglyLinkedList.cs
+++ b/Orm/Xtensive.Orm/Collections/SinglyLinkedList.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.11.19
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 namespace Xtensive.Collections
 {
diff --git a/Orm/Xtensive.Orm/Collections/TopDeque.cs b/Orm/Xtensive.Orm/Collections/TopDeque.cs
index 026b42675a..3cef977d33 100644
--- a/Orm/Xtensive.Orm/Collections/TopDeque.cs
+++ b/Orm/Xtensive.Orm/Collections/TopDeque.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Ustinov
 // Created:    2007.05.28
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Collections/TypeRegistration.cs b/Orm/Xtensive.Orm/Collections/TypeRegistration.cs
index 0190877dec..e737fea7d0 100644
--- a/Orm/Xtensive.Orm/Collections/TypeRegistration.cs
+++ b/Orm/Xtensive.Orm/Collections/TypeRegistration.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.21
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Collections/TypeRegistrationProcessorBase.cs b/Orm/Xtensive.Orm/Collections/TypeRegistrationProcessorBase.cs
index fafe28746b..261b209e14 100644
--- a/Orm/Xtensive.Orm/Collections/TypeRegistrationProcessorBase.cs
+++ b/Orm/Xtensive.Orm/Collections/TypeRegistrationProcessorBase.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.11.23
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Collections/TypeRegistry.cs b/Orm/Xtensive.Orm/Collections/TypeRegistry.cs
index 80c02cb435..1ca57e5721 100644
--- a/Orm/Xtensive.Orm/Collections/TypeRegistry.cs
+++ b/Orm/Xtensive.Orm/Collections/TypeRegistry.cs
@@ -4,12 +4,9 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.03
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.IoC;
 
diff --git a/Orm/Xtensive.Orm/Comparison/AdvancedComparer.cs b/Orm/Xtensive.Orm/Comparison/AdvancedComparer.cs
index 1aa4688be7..3ef7773ae8 100644
--- a/Orm/Xtensive.Orm/Comparison/AdvancedComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/AdvancedComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.08
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Comparison/AdvancedComparerBase.cs b/Orm/Xtensive.Orm/Comparison/AdvancedComparerBase.cs
index d435561c83..585e3f577a 100644
--- a/Orm/Xtensive.Orm/Comparison/AdvancedComparerBase.cs
+++ b/Orm/Xtensive.Orm/Comparison/AdvancedComparerBase.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.23
 
-using System;
 using System.Collections;
 using System.Collections.Concurrent;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm/Comparison/AdvancedComparerStruct.cs b/Orm/Xtensive.Orm/Comparison/AdvancedComparerStruct.cs
index c8de58fd89..3e80bf68ea 100644
--- a/Orm/Xtensive.Orm/Comparison/AdvancedComparerStruct.cs
+++ b/Orm/Xtensive.Orm/Comparison/AdvancedComparerStruct.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.10
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Comparison/CastingComparer.cs b/Orm/Xtensive.Orm/Comparison/CastingComparer.cs
index 77033a2e58..9fd0aa5ba9 100644
--- a/Orm/Xtensive.Orm/Comparison/CastingComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/CastingComparer.cs
@@ -4,7 +4,6 @@
 // Created by: 
 // Created:    2008.03.06
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Conversion;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/ComparerProvider.cs b/Orm/Xtensive.Orm/Comparison/ComparerProvider.cs
index 1adec5cc24..43841d9b72 100644
--- a/Orm/Xtensive.Orm/Comparison/ComparerProvider.cs
+++ b/Orm/Xtensive.Orm/Comparison/ComparerProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2008.01.14
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/ComparisonRule.cs b/Orm/Xtensive.Orm/Comparison/ComparisonRule.cs
index b38e14d4cf..994464b3ea 100644
--- a/Orm/Xtensive.Orm/Comparison/ComparisonRule.cs
+++ b/Orm/Xtensive.Orm/Comparison/ComparisonRule.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.05
 
-using System;
 using System.Globalization;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Comparison/ComparisonRules.cs b/Orm/Xtensive.Orm/Comparison/ComparisonRules.cs
index f72e43309f..618d82e683 100644
--- a/Orm/Xtensive.Orm/Comparison/ComparisonRules.cs
+++ b/Orm/Xtensive.Orm/Comparison/ComparisonRules.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.02.04
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/Interfaces/IAdvancedComparer.cs b/Orm/Xtensive.Orm/Comparison/Interfaces/IAdvancedComparer.cs
index fd2e92a866..589beb1d24 100644
--- a/Orm/Xtensive.Orm/Comparison/Interfaces/IAdvancedComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Interfaces/IAdvancedComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Comparison
 {
diff --git a/Orm/Xtensive.Orm/Comparison/Interfaces/IComparerProvider.cs b/Orm/Xtensive.Orm/Comparison/Interfaces/IComparerProvider.cs
index 9caf4aad5d..f554e15348 100644
--- a/Orm/Xtensive.Orm/Comparison/Interfaces/IComparerProvider.cs
+++ b/Orm/Xtensive.Orm/Comparison/Interfaces/IComparerProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2008.01.14
 
-using System.Collections.Generic;
 
 namespace Xtensive.Comparison
 {
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/ArrayComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/ArrayComparer.cs
index e775b06735..37bfd581c0 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/ArrayComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/ArrayComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.16
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/AssemblyComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/AssemblyComparer.cs
index af3e73747c..c3a78266d8 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/AssemblyComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/AssemblyComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
 using System.Reflection;
 using System.Runtime.Serialization;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/BaseComparerWrapper.cs b/Orm/Xtensive.Orm/Comparison/Internals/BaseComparerWrapper.cs
index ef4e624db5..a6c62e300a 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/BaseComparerWrapper.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/BaseComparerWrapper.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/BooleanComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/BooleanComparer.cs
index 0b5fd6ad66..6aa4c84202 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/BooleanComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/BooleanComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/ByteComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/ByteComparer.cs
index ebef970319..f026dcd83b 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/ByteComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/ByteComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/CharComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/CharComparer.cs
index 6a2eca9ed3..f2bc9c2af3 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/CharComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/CharComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/DecimalComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/DecimalComparer.cs
index 2190b2c798..83abb70f64 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/DecimalComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/DecimalComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/DoubleComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/DoubleComparer.cs
index 7d8fe11676..06d46030c0 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/DoubleComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/DoubleComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/EnumComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/EnumComparer.cs
index fd904619e7..5d283ad010 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/EnumComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/EnumComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.23
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/EnumerableInterfaceComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/EnumerableInterfaceComparer.cs
index af58960478..e8e24c2a2b 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/EnumerableInterfaceComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/EnumerableInterfaceComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.16
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/GuidComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/GuidComparer.cs
index 42271594d1..ba69576c6d 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/GuidComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/GuidComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/Int16Comparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/Int16Comparer.cs
index fe10bc5856..d975f81e8c 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/Int16Comparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/Int16Comparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/Int32Comparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/Int32Comparer.cs
index bbe22f1d08..db0a84eba4 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/Int32Comparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/Int32Comparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/Int64Comparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/Int64Comparer.cs
index 50dfb9d1cf..eb75856395 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/Int64Comparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/Int64Comparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/KeyValuePairComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/KeyValuePairComparer.cs
index c61ff9bf51..a3be09995a 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/KeyValuePairComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/KeyValuePairComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/NoSystemComparerHandler.cs b/Orm/Xtensive.Orm/Comparison/Internals/NoSystemComparerHandler.cs
index 5322856c92..930cd8c89a 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/NoSystemComparerHandler.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/NoSystemComparerHandler.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.10
 
-using System;
 using Xtensive.Reflection;
 
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/NullableComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/NullableComparer.cs
index 935248b46d..0abbd273cc 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/NullableComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/NullableComparer.cs
@@ -4,7 +4,6 @@
 // Created by: 
 // Created:    2008.01.23
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/ObjectComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/ObjectComparer.cs
index f53972f328..bbb291972c 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/ObjectComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/ObjectComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.23
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T1,T2}.cs b/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T1,T2}.cs
index db277ef564..6a232c3657 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T1,T2}.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T1,T2}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T}.cs b/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T}.cs
index 86d7f2ffee..ca6dd28883 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T}.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/PairComparer{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/SByteComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/SByteComparer.cs
index 720d62b587..36ce588f89 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/SByteComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/SByteComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/SingleComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/SingleComparer.cs
index a7c901bbea..db8245c596 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/SingleComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/SingleComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2007.11.14
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/StringComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/StringComparer.cs
index 006eacfcfc..73b737f9d7 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/StringComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/StringComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Globalization;
 using System.Runtime.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/SystemComparerStruct.cs b/Orm/Xtensive.Orm/Comparison/Internals/SystemComparerStruct.cs
index ee6930f159..a1bfe0fd10 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/SystemComparerStruct.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/SystemComparerStruct.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.10
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/TupleComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/TupleComparer.cs
index 98fd931711..6b99965481 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/TupleComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/TupleComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.29
 
-using System;
 using System.Runtime.Serialization;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/TupleDescriptorComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/TupleDescriptorComparer.cs
index 8252629ebe..975d708e6b 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/TupleDescriptorComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/TupleDescriptorComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
 using System.Reflection;
 using System.Runtime.Serialization;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/TypeComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/TypeComparer.cs
index ada19dc974..a3a13d548f 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/TypeComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/TypeComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.22
 
-using System;
 using System.Collections.Concurrent;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/UInt16Comparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/UInt16Comparer.cs
index 19c230f0f8..7128b8f070 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/UInt16Comparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/UInt16Comparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/UInt32Comparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/UInt32Comparer.cs
index 31c0fecb52..b50a0be508 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/UInt32Comparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/UInt32Comparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/UInt64Comparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/UInt64Comparer.cs
index 5fc58bfe5c..9174f37b82 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/UInt64Comparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/UInt64Comparer.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.11.28
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparer.cs b/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparer.cs
index 6bb7a151b9..ad251f720c 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.23
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using System.Runtime.Serialization;
 
diff --git a/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparerBase.cs b/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparerBase.cs
index 19a457b3cb..131fb40764 100644
--- a/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparerBase.cs
+++ b/Orm/Xtensive.Orm/Comparison/Internals/ValueTypeComparerBase.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.23
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using System.Runtime.Serialization;
 
diff --git a/Orm/Xtensive.Orm/Comparison/ReferenceEqualityComparer.cs b/Orm/Xtensive.Orm/Comparison/ReferenceEqualityComparer.cs
index 83ad94a00c..9f06a204bc 100644
--- a/Orm/Xtensive.Orm/Comparison/ReferenceEqualityComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/ReferenceEqualityComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.09.01
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
diff --git a/Orm/Xtensive.Orm/Comparison/SystemComparer.cs b/Orm/Xtensive.Orm/Comparison/SystemComparer.cs
index e83903d374..25e2f2a1bd 100644
--- a/Orm/Xtensive.Orm/Comparison/SystemComparer.cs
+++ b/Orm/Xtensive.Orm/Comparison/SystemComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.10
 
-using System;
 using System.Runtime.Serialization;
 
 namespace Xtensive.Comparison
diff --git a/Orm/Xtensive.Orm/Comparison/SystemComparerProvider.cs b/Orm/Xtensive.Orm/Comparison/SystemComparerProvider.cs
index a717aa7384..28590a3e0a 100644
--- a/Orm/Xtensive.Orm/Comparison/SystemComparerProvider.cs
+++ b/Orm/Xtensive.Orm/Comparison/SystemComparerProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.10
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 
diff --git a/Orm/Xtensive.Orm/Comparison/ValueRangeInfo.cs b/Orm/Xtensive.Orm/Comparison/ValueRangeInfo.cs
index 45047bd350..762aae4dfe 100644
--- a/Orm/Xtensive.Orm/Comparison/ValueRangeInfo.cs
+++ b/Orm/Xtensive.Orm/Comparison/ValueRangeInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.23
 
-using System;
 using Xtensive.Arithmetic;
 
 
diff --git a/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase1,TBase2}.cs b/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase1,TBase2}.cs
index 70dcb62601..3fa2efeb22 100644
--- a/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase1,TBase2}.cs
+++ b/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase1,TBase2}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.21
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase}.cs b/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase}.cs
index 9b802f23a8..631dcc6f14 100644
--- a/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase}.cs
+++ b/Orm/Xtensive.Orm/Comparison/WrappingComparer{T,TBase}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.21
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Conversion/AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/AdvancedConverter.cs
index 2d5bc7e347..f7fe28ae88 100644
--- a/Orm/Xtensive.Orm/Conversion/AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/AdvancedConverter.cs
@@ -4,10 +4,8 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.15
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
-using System.Threading;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Conversion/AdvancedConverterBase.cs b/Orm/Xtensive.Orm/Conversion/AdvancedConverterBase.cs
index e42ed05a7e..9fcb0f6a81 100644
--- a/Orm/Xtensive.Orm/Conversion/AdvancedConverterBase.cs
+++ b/Orm/Xtensive.Orm/Conversion/AdvancedConverterBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.15
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Conversion/AdvancedConverterProvider.cs b/Orm/Xtensive.Orm/Conversion/AdvancedConverterProvider.cs
index b676265f80..256fabf21a 100644
--- a/Orm/Xtensive.Orm/Conversion/AdvancedConverterProvider.cs
+++ b/Orm/Xtensive.Orm/Conversion/AdvancedConverterProvider.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Threading;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Conversion/AdvancedConverterStruct.cs b/Orm/Xtensive.Orm/Conversion/AdvancedConverterStruct.cs
index a03d971d46..2f6426a42d 100644
--- a/Orm/Xtensive.Orm/Conversion/AdvancedConverterStruct.cs
+++ b/Orm/Xtensive.Orm/Conversion/AdvancedConverterStruct.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.15
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Conversion/Biconverter.cs b/Orm/Xtensive.Orm/Conversion/Biconverter.cs
index 174512e7d1..3560c4f334 100644
--- a/Orm/Xtensive.Orm/Conversion/Biconverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Biconverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.10.03
 
-using System;
 
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/ConvertingEnumerable.cs b/Orm/Xtensive.Orm/Conversion/ConvertingEnumerable.cs
index f533c00286..825aa7faf4 100644
--- a/Orm/Xtensive.Orm/Conversion/ConvertingEnumerable.cs
+++ b/Orm/Xtensive.Orm/Conversion/ConvertingEnumerable.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Ilyin
 // Created:    2007.06.04
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterFactory.cs b/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterFactory.cs
index 1662f4a048..4b6085be2f 100644
--- a/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterFactory.cs
+++ b/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterFactory.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.14
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterProvider.cs b/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterProvider.cs
index 815d0df38d..6d7a9ae995 100644
--- a/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterProvider.cs
+++ b/Orm/Xtensive.Orm/Conversion/Interfaces/IAdvancedConverterProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/BooleanAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/BooleanAdvancedConverter.cs
index 61bd631af9..13ffa80805 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/BooleanAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/BooleanAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.22
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/ByteAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/ByteAdvancedConverter.cs
index b0ec7e77f6..30392515d3 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/ByteAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/ByteAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.22
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/ByteRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/ByteRoughAdvancedConverter.cs
index 1156171516..2779ca74f8 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/ByteRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/ByteRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/CharAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/CharAdvancedConverter.cs
index 0e1ee35ccd..188069d5ef 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/CharAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/CharAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/ConvertingEnumerator.cs b/Orm/Xtensive.Orm/Conversion/Internals/ConvertingEnumerator.cs
index f68f5dc513..cb05990ff5 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/ConvertingEnumerator.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/ConvertingEnumerator.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Ilyin
 // Created:    2007.06.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/DateTimeAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/DateTimeAdvancedConverter.cs
index ee3cfa080d..c36edc8229 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/DateTimeAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/DateTimeAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/DateTimeRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/DateTimeRoughAdvancedConverter.cs
index 278fcb2b2d..3f9214961f 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/DateTimeRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/DateTimeRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/DecimalAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/DecimalAdvancedConverter.cs
index f1884ea861..098892c3ec 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/DecimalAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/DecimalAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/DecimalRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/DecimalRoughAdvancedConverter.cs
index c3bfa09969..eb60476272 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/DecimalRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/DecimalRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/DoubleAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/DoubleAdvancedConverter.cs
index 0e96e47d34..0daab0d8c7 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/DoubleAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/DoubleAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/DoubleRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/DoubleRoughAdvancedConverter.cs
index c1650425c5..708ab0c60d 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/DoubleRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/DoubleRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverterFactory.cs b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverterFactory.cs
index 631ac2a911..05b8780729 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverterFactory.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverterFactory.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.14
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TIntermediate}.cs b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TIntermediate}.cs
index d6a6088ad2..03faa7564e 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TIntermediate}.cs	
+++ b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TIntermediate}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.15
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TUnderlyingFrom, TUnderlyingTo}.cs b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TUnderlyingFrom, TUnderlyingTo}.cs
index c8e691cd43..928fbb87b0 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TUnderlyingFrom, TUnderlyingTo}.cs	
+++ b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo, TUnderlyingFrom, TUnderlyingTo}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.14
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo}.cs b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo}.cs
index 6f52122279..049619f9b2 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo}.cs	
+++ b/Orm/Xtensive.Orm/Conversion/Internals/EnumAdvancedConverter{TFrom, TTo}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.15
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/GuidAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/GuidAdvancedConverter.cs
index 96ab72e772..3b8f1f1789 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/GuidAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/GuidAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/Int16AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/Int16AdvancedConverter.cs
index 8d13df7bcf..dd89008334 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/Int16AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/Int16AdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.22
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/Int16RoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/Int16RoughAdvancedConverter.cs
index 4c251aab93..d4638afaff 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/Int16RoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/Int16RoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/Int32AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/Int32AdvancedConverter.cs
index b1c6a4baaf..23ca8caa09 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/Int32AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/Int32AdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/Int32RoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/Int32RoughAdvancedConverter.cs
index 6bd798c01e..e1cbe352ab 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/Int32RoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/Int32RoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/Int64AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/Int64AdvancedConverter.cs
index 2e2f5dd3a3..1f191240a5 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/Int64AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/Int64AdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.22
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/Int64RoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/Int64RoughAdvancedConverter.cs
index 3a1c786c3d..5374e9e768 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/Int64RoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/Int64RoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/NullableAdvancedConverterFactory.cs b/Orm/Xtensive.Orm/Conversion/Internals/NullableAdvancedConverterFactory.cs
index 5536d234dc..f826ee71b2 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/NullableAdvancedConverterFactory.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/NullableAdvancedConverterFactory.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.14
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/NullableForwardAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/NullableForwardAdvancedConverter.cs
index 4bca7a5c8f..2ffa8c9131 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/NullableForwardAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/NullableForwardAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.13
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/NullableNullableAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/NullableNullableAdvancedConverter.cs
index 0a3a62950d..9117e1b762 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/NullableNullableAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/NullableNullableAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.13
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/NullableReverseAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/NullableReverseAdvancedConverter.cs
index cff8e55ac1..73ef7e87db 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/NullableReverseAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/NullableReverseAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.13
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/ObjectAdvancedConverterFactory.cs b/Orm/Xtensive.Orm/Conversion/Internals/ObjectAdvancedConverterFactory.cs
index 600d8a691a..feea094030 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/ObjectAdvancedConverterFactory.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/ObjectAdvancedConverterFactory.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.03.08
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/ObjectToBaseAdvancedConverter{TFrom, TTo}.cs b/Orm/Xtensive.Orm/Conversion/Internals/ObjectToBaseAdvancedConverter{TFrom, TTo}.cs
index 64361596bc..bb70bce42b 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/ObjectToBaseAdvancedConverter{TFrom, TTo}.cs	
+++ b/Orm/Xtensive.Orm/Conversion/Internals/ObjectToBaseAdvancedConverter{TFrom, TTo}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.03.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/ObjectToDescendantAdvancedConverter{TFrom, TTo}.cs b/Orm/Xtensive.Orm/Conversion/Internals/ObjectToDescendantAdvancedConverter{TFrom, TTo}.cs
index 78f8c0a9cd..d08003ca0d 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/ObjectToDescendantAdvancedConverter{TFrom, TTo}.cs	
+++ b/Orm/Xtensive.Orm/Conversion/Internals/ObjectToDescendantAdvancedConverter{TFrom, TTo}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.03.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/RoughAdvancedConverterBase.cs b/Orm/Xtensive.Orm/Conversion/Internals/RoughAdvancedConverterBase.cs
index 18cdcbf57e..ef0bd2fb1d 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/RoughAdvancedConverterBase.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/RoughAdvancedConverterBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/SByteAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/SByteAdvancedConverter.cs
index 5de87348ff..8a888c48a7 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/SByteAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/SByteAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.22
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/SByteRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/SByteRoughAdvancedConverter.cs
index 192c75ca58..af9972b8b4 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/SByteRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/SByteRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/SingleAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/SingleAdvancedConverter.cs
index 149ce9b75d..59b2f4cd14 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/SingleAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/SingleAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/SingleRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/SingleRoughAdvancedConverter.cs
index e58d3474f5..4dcf824d0a 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/SingleRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/SingleRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/StrictAdvancedConverterBase.cs b/Orm/Xtensive.Orm/Conversion/Internals/StrictAdvancedConverterBase.cs
index 18792846e2..dad53b1c95 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/StrictAdvancedConverterBase.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/StrictAdvancedConverterBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/StringAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/StringAdvancedConverter.cs
index 7288bca1c8..9498e95f55 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/StringAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/StringAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.21
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter.cs
index acb2dbdc78..243007c8fb 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter{T}.cs b/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter{T}.cs
index f2d6d2dc7d..6be3d4fa88 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter{T}.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/StringRoughAdvancedConverter{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanAdvancedConverter.cs
index a03b9d3a87..6230d9fb8e 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.11.11
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanRoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanRoughAdvancedConverter.cs
index 044131728e..c0fa1a5228 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanRoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/TimeSpanRoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.11.12
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/TypeAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/TypeAdvancedConverter.cs
index 0241bfe769..3cddabacc7 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/TypeAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/TypeAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.26
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/UInt16AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/UInt16AdvancedConverter.cs
index a50db528a3..6e7407cab5 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/UInt16AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/UInt16AdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/UInt16RoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/UInt16RoughAdvancedConverter.cs
index 25630838db..5250e18de3 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/UInt16RoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/UInt16RoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/UInt32AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/UInt32AdvancedConverter.cs
index 6a32e8d6e2..eba1f879d1 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/UInt32AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/UInt32AdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/UInt32RoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/UInt32RoughAdvancedConverter.cs
index 922127759f..5623e6f332 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/UInt32RoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/UInt32RoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/UInt64AdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/UInt64AdvancedConverter.cs
index 0391cf95d3..87d38f2274 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/UInt64AdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/UInt64AdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Roman Churakov
 // Created:    2008.01.23
 
-using System;
 using System.Globalization;
 
 namespace Xtensive.Conversion
diff --git a/Orm/Xtensive.Orm/Conversion/Internals/UInt64RoughAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/Internals/UInt64RoughAdvancedConverter.cs
index e2878dc4fa..834a778452 100644
--- a/Orm/Xtensive.Orm/Conversion/Internals/UInt64RoughAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/Internals/UInt64RoughAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.08
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Conversion/WrappingAdvancedConverter.cs b/Orm/Xtensive.Orm/Conversion/WrappingAdvancedConverter.cs
index 51eef3c4e0..83f0c5f500 100644
--- a/Orm/Xtensive.Orm/Conversion/WrappingAdvancedConverter.cs
+++ b/Orm/Xtensive.Orm/Conversion/WrappingAdvancedConverter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.02.13
 
-using System;
 
 namespace Xtensive.Conversion
 {
diff --git a/Orm/Xtensive.Orm/Core/AliasGenerator.cs b/Orm/Xtensive.Orm/Core/AliasGenerator.cs
index 8550343d47..f981de9371 100644
--- a/Orm/Xtensive.Orm/Core/AliasGenerator.cs
+++ b/Orm/Xtensive.Orm/Core/AliasGenerator.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.10
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/ArgumentValidator.cs b/Orm/Xtensive.Orm/Core/ArgumentValidator.cs
index d8da37ab08..0ee61508ba 100644
--- a/Orm/Xtensive.Orm/Core/ArgumentValidator.cs
+++ b/Orm/Xtensive.Orm/Core/ArgumentValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.01
 
-using System;
 using System.Runtime.CompilerServices;
 using JetBrains.Annotations;
 using Xtensive.Comparison;
diff --git a/Orm/Xtensive.Orm/Core/AssociateProvider.cs b/Orm/Xtensive.Orm/Core/AssociateProvider.cs
index 076da2971f..5226d5f51a 100644
--- a/Orm/Xtensive.Orm/Core/AssociateProvider.cs
+++ b/Orm/Xtensive.Orm/Core/AssociateProvider.cs
@@ -4,15 +4,12 @@
 // Created by: Alexey Gamzov
 // Created:    2008.01.18
 
-using System;
-using System.Collections.Generic;
 using System.Collections.Concurrent;
 using System.Diagnostics;
 using System.Reflection;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Text;
-using System.Threading;
 using Xtensive.Comparison;
 
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Core/AsyncFutureResult.cs b/Orm/Xtensive.Orm/Core/AsyncFutureResult.cs
index c48216f334..c70728079a 100644
--- a/Orm/Xtensive.Orm/Core/AsyncFutureResult.cs
+++ b/Orm/Xtensive.Orm/Core/AsyncFutureResult.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.12
 
-using System;
 using Xtensive.Orm.Logging;
-using System.Threading.Tasks;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/ConfigurationCollection.cs b/Orm/Xtensive.Orm/Core/ConfigurationCollection.cs
index 3300408d78..6332b423c7 100644
--- a/Orm/Xtensive.Orm/Core/ConfigurationCollection.cs
+++ b/Orm/Xtensive.Orm/Core/ConfigurationCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.08.07
 
-using System.Collections.Generic;
 using System.Configuration;
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Context.cs b/Orm/Xtensive.Orm/Core/Context.cs
index 25bda7e2c6..1031f0c471 100644
--- a/Orm/Xtensive.Orm/Core/Context.cs
+++ b/Orm/Xtensive.Orm/Core/Context.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.15
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Direction.cs b/Orm/Xtensive.Orm/Core/Direction.cs
index be1ab678b4..b2d3994e6b 100644
--- a/Orm/Xtensive.Orm/Core/Direction.cs
+++ b/Orm/Xtensive.Orm/Core/Direction.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.09.10
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Disposable.cs b/Orm/Xtensive.Orm/Core/Disposable.cs
index 8b1a5adfc6..ac5af28f8f 100644
--- a/Orm/Xtensive.Orm/Core/Disposable.cs
+++ b/Orm/Xtensive.Orm/Core/Disposable.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/DisposableSet.cs b/Orm/Xtensive.Orm/Core/DisposableSet.cs
index 0b2e88ee0a..f1b295b4f8 100644
--- a/Orm/Xtensive.Orm/Core/DisposableSet.cs
+++ b/Orm/Xtensive.Orm/Core/DisposableSet.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.29
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Core/Disposable{T1,T2}.cs b/Orm/Xtensive.Orm/Core/Disposable{T1,T2}.cs
index b33abe1c7c..bbc0092373 100644
--- a/Orm/Xtensive.Orm/Core/Disposable{T1,T2}.cs
+++ b/Orm/Xtensive.Orm/Core/Disposable{T1,T2}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Disposable{T}.cs b/Orm/Xtensive.Orm/Core/Disposable{T}.cs
index 81c91206c1..1215954a86 100644
--- a/Orm/Xtensive.Orm/Core/Disposable{T}.cs
+++ b/Orm/Xtensive.Orm/Core/Disposable{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/EnumeratorExtensions.cs b/Orm/Xtensive.Orm/Core/EnumeratorExtensions.cs
index b44745ffff..e46005e7a4 100644
--- a/Orm/Xtensive.Orm/Core/EnumeratorExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/EnumeratorExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.06.24
 
-using System.Collections.Generic;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/ExceptionAggregator.cs b/Orm/Xtensive.Orm/Core/ExceptionAggregator.cs
index 5a7dd6b345..e832a24133 100644
--- a/Orm/Xtensive.Orm/Core/ExceptionAggregator.cs
+++ b/Orm/Xtensive.Orm/Core/ExceptionAggregator.cs
@@ -4,12 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.04
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
-using System.Threading.Tasks;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Core/Exceptions.cs b/Orm/Xtensive.Orm/Core/Exceptions.cs
index 18a80be3a7..0d5555d427 100644
--- a/Orm/Xtensive.Orm/Core/Exceptions.cs
+++ b/Orm/Xtensive.Orm/Core/Exceptions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.10.03
 
-using System;
 using System.Linq.Expressions;
 using JetBrains.Annotations;
 using Xtensive.Orm.Logging;
diff --git a/Orm/Xtensive.Orm/Core/Exceptions/ActivationException.cs b/Orm/Xtensive.Orm/Core/Exceptions/ActivationException.cs
index 12a737343f..8e11af8ea7 100644
--- a/Orm/Xtensive.Orm/Core/Exceptions/ActivationException.cs
+++ b/Orm/Xtensive.Orm/Core/Exceptions/ActivationException.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
 using System.Runtime.Serialization;
 
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Core/Exceptions/AggregateException.cs b/Orm/Xtensive.Orm/Core/Exceptions/AggregateException.cs
index 928e627457..0443f08924 100644
--- a/Orm/Xtensive.Orm/Core/Exceptions/AggregateException.cs
+++ b/Orm/Xtensive.Orm/Core/Exceptions/AggregateException.cs
@@ -4,13 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.03
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Text;
-using System.Linq;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Exceptions/InstanceIsLockedException.cs b/Orm/Xtensive.Orm/Core/Exceptions/InstanceIsLockedException.cs
index 17f8ec1645..c9267ac89a 100644
--- a/Orm/Xtensive.Orm/Core/Exceptions/InstanceIsLockedException.cs
+++ b/Orm/Xtensive.Orm/Core/Exceptions/InstanceIsLockedException.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.06.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Core/Extensions/ArrayExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/ArrayExtensions.cs
index 6bcfc17108..12a90a9fb5 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/ArrayExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/ArrayExtensions.cs
@@ -5,8 +5,6 @@
 // Reimplemented by: Dmitri Maximov
 // Created:    2007.07.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Comparison;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Core/Extensions/CollectionExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/CollectionExtensions.cs
index 8a34b071ce..744f4ad47d 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/CollectionExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/CollectionExtensions.cs
@@ -5,9 +5,6 @@
 // Reimplemented by: Dmitri Maximov
 // Created:    2007.07.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Extensions/DelegateBindExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/DelegateBindExtensions.cs
index eed2a6c16c..d35f4620a7 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/DelegateBindExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/DelegateBindExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Extensions/DisposableExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/DisposableExtensions.cs
index 22f6c1c145..69d8d7b09d 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/DisposableExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/DisposableExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.05.14
 
-using System;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Extensions/EnumerableExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/EnumerableExtensions.cs
index 06d6329dac..9c4f9b545f 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/EnumerableExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/EnumerableExtensions.cs
@@ -4,14 +4,9 @@
 // Created by: Alex Yakunin
 // Created:    2008.05.16
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Collections;
 using Xtensive.Collections.Graphs;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm/Core/Extensions/ExpressionCompileExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/ExpressionCompileExtensions.cs
index bc1c92ac20..469881a100 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/ExpressionCompileExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/ExpressionCompileExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.07
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Linq;
 
diff --git a/Orm/Xtensive.Orm/Core/Extensions/ExpressionExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/ExpressionExtensions.cs
index 2196f55ff6..4ed63c2036 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/ExpressionExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/ExpressionExtensions.cs
@@ -4,14 +4,12 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.21
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Linq;
 using Xtensive.Linq.SerializableExpressions;
 using Xtensive.Linq.SerializableExpressions.Internals;
 
-using System.Linq;
 using Xtensive.Reflection;
 using System.Collections.Concurrent;
 
diff --git a/Orm/Xtensive.Orm/Core/Extensions/HasServicesExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/HasServicesExtensions.cs
index 4e65fb95ee..998442c61d 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/HasServicesExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/HasServicesExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.15
 
-using System;
 using Xtensive.Core;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Core/Extensions/ListExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/ListExtensions.cs
index d50fdcb846..9d2c6fb22f 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/ListExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/ListExtensions.cs
@@ -5,9 +5,7 @@
 // Reimplemented by: Dmitri Maximov
 // Created:    2007.07.04
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Extensions/ServiceContainerExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/ServiceContainerExtensions.cs
index 6160475bf2..2c5a86e6e8 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/ServiceContainerExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/ServiceContainerExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.02
 
-using System;
 using JetBrains.Annotations;
 using Xtensive.Reflection;
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Core/Extensions/StringBuilderExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/StringBuilderExtensions.cs
index 741b692b63..593e0af1a6 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/StringBuilderExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/StringBuilderExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.07.30
 
-using System;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Core/Extensions/StringExtensions.cs b/Orm/Xtensive.Orm/Core/Extensions/StringExtensions.cs
index 9548948a01..a8ebddaee3 100644
--- a/Orm/Xtensive.Orm/Core/Extensions/StringExtensions.cs
+++ b/Orm/Xtensive.Orm/Core/Extensions/StringExtensions.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.18
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
 
diff --git a/Orm/Xtensive.Orm/Core/FutureResult.cs b/Orm/Xtensive.Orm/Core/FutureResult.cs
index 5e9cf5f353..7d3899b1b5 100644
--- a/Orm/Xtensive.Orm/Core/FutureResult.cs
+++ b/Orm/Xtensive.Orm/Core/FutureResult.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.15
 
-using System;
-using System.Threading.Tasks;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/HasVersion{TValue,TVersion}.cs b/Orm/Xtensive.Orm/Core/HasVersion{TValue,TVersion}.cs
index 630107db85..9fb4e313f1 100644
--- a/Orm/Xtensive.Orm/Core/HasVersion{TValue,TVersion}.cs
+++ b/Orm/Xtensive.Orm/Core/HasVersion{TValue,TVersion}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ustinov
 // Created:    2007.06.01
 
-using System;
 using System.Diagnostics;
 using Xtensive.Comparison;
 
diff --git a/Orm/Xtensive.Orm/Core/InheritableScope.cs b/Orm/Xtensive.Orm/Core/InheritableScope.cs
index 3e5ca969be..938891bb24 100644
--- a/Orm/Xtensive.Orm/Core/InheritableScope.cs
+++ b/Orm/Xtensive.Orm/Core/InheritableScope.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.05.05
 
-using System;
 using System.Security;
 
 
diff --git a/Orm/Xtensive.Orm/Core/Interfaces/IContext.cs b/Orm/Xtensive.Orm/Core/Interfaces/IContext.cs
index c09293b611..26aca0b3fe 100644
--- a/Orm/Xtensive.Orm/Core/Interfaces/IContext.cs
+++ b/Orm/Xtensive.Orm/Core/Interfaces/IContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.31
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Interfaces/IContext{TScope}.cs b/Orm/Xtensive.Orm/Core/Interfaces/IContext{TScope}.cs
index f29a6e2e66..4c89fecf90 100644
--- a/Orm/Xtensive.Orm/Core/Interfaces/IContext{TScope}.cs
+++ b/Orm/Xtensive.Orm/Core/Interfaces/IContext{TScope}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.12.31
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Interfaces/IHasServices.cs b/Orm/Xtensive.Orm/Core/Interfaces/IHasServices.cs
index 7391d6e38e..211ffe57ad 100644
--- a/Orm/Xtensive.Orm/Core/Interfaces/IHasServices.cs
+++ b/Orm/Xtensive.Orm/Core/Interfaces/IHasServices.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.15
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Interfaces/IIdentified.cs b/Orm/Xtensive.Orm/Core/Interfaces/IIdentified.cs
index 5904aa0561..684bcab496 100644
--- a/Orm/Xtensive.Orm/Core/Interfaces/IIdentified.cs
+++ b/Orm/Xtensive.Orm/Core/Interfaces/IIdentified.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.05.01
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/Internals/ValueStringBuilder.cs b/Orm/Xtensive.Orm/Core/Internals/ValueStringBuilder.cs
index 1fad96af0e..50c60a7168 100644
--- a/Orm/Xtensive.Orm/Core/Internals/ValueStringBuilder.cs
+++ b/Orm/Xtensive.Orm/Core/Internals/ValueStringBuilder.cs
@@ -5,7 +5,6 @@
 // + re-structured to fit project rules
 // + formatting rules applied
 
-using System;
 using System.Buffers;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
diff --git a/Orm/Xtensive.Orm/Core/JoiningDisposable.cs b/Orm/Xtensive.Orm/Core/JoiningDisposable.cs
index 9304c86c23..2f701a67b3 100644
--- a/Orm/Xtensive.Orm/Core/JoiningDisposable.cs
+++ b/Orm/Xtensive.Orm/Core/JoiningDisposable.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.27
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Core/LockableBase.cs b/Orm/Xtensive.Orm/Core/LockableBase.cs
index 48cb59a6d9..1b4d747089 100644
--- a/Orm/Xtensive.Orm/Core/LockableBase.cs
+++ b/Orm/Xtensive.Orm/Core/LockableBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.11.22
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Core/MatchType.cs b/Orm/Xtensive.Orm/Core/MatchType.cs
index 3d8d09bc2d..94d523c869 100644
--- a/Orm/Xtensive.Orm/Core/MatchType.cs
+++ b/Orm/Xtensive.Orm/Core/MatchType.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.12.25
 
-using System;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/Core/MethodCacheBase.cs b/Orm/Xtensive.Orm/Core/MethodCacheBase.cs
index 6506dd2e32..9932ece5f0 100644
--- a/Orm/Xtensive.Orm/Core/MethodCacheBase.cs
+++ b/Orm/Xtensive.Orm/Core/MethodCacheBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.10
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Core/Pair{TFirst,TSecond}.cs b/Orm/Xtensive.Orm/Core/Pair{TFirst,TSecond}.cs
index af240475fb..969b4dd1a8 100644
--- a/Orm/Xtensive.Orm/Core/Pair{TFirst,TSecond}.cs
+++ b/Orm/Xtensive.Orm/Core/Pair{TFirst,TSecond}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ustinov
 // Created:    2007.06.01
 
-using System;
 using System.Diagnostics;
 using Xtensive.Comparison;
 
diff --git a/Orm/Xtensive.Orm/Core/Pair{T}.cs b/Orm/Xtensive.Orm/Core/Pair{T}.cs
index 96a40c8524..acdde43701 100644
--- a/Orm/Xtensive.Orm/Core/Pair{T}.cs
+++ b/Orm/Xtensive.Orm/Core/Pair{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Ustinov
 // Created:    2007.06.01
 
-using System;
 using System.Diagnostics;
 using Xtensive.Comparison;
 
diff --git a/Orm/Xtensive.Orm/Core/ParameterContext.cs b/Orm/Xtensive.Orm/Core/ParameterContext.cs
index 2829d67eed..9d7e5d19a2 100644
--- a/Orm/Xtensive.Orm/Core/ParameterContext.cs
+++ b/Orm/Xtensive.Orm/Core/ParameterContext.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.08.14
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Core/Parameter{TValue}.cs b/Orm/Xtensive.Orm/Core/Parameter{TValue}.cs
index fcafb9afa3..c3823011ab 100644
--- a/Orm/Xtensive.Orm/Core/Parameter{TValue}.cs
+++ b/Orm/Xtensive.Orm/Core/Parameter{TValue}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.08.14
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Scope.cs b/Orm/Xtensive.Orm/Core/Scope.cs
index e67de0408b..9632cfec2e 100644
--- a/Orm/Xtensive.Orm/Core/Scope.cs
+++ b/Orm/Xtensive.Orm/Core/Scope.cs
@@ -4,11 +4,9 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.27
 
-using System;
 using System.Diagnostics;
 using System.Runtime.ExceptionServices;
 using System.Security;
-using System.Threading;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/Segment.cs b/Orm/Xtensive.Orm/Core/Segment.cs
index a04902dcd6..da948d86a7 100644
--- a/Orm/Xtensive.Orm/Core/Segment.cs
+++ b/Orm/Xtensive.Orm/Core/Segment.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.05.30
 
-using System;
 using System.Diagnostics;
 using Xtensive.Arithmetic;
 using Xtensive.Comparison;
diff --git a/Orm/Xtensive.Orm/Core/SimpleScope.cs b/Orm/Xtensive.Orm/Core/SimpleScope.cs
index d758f6b23c..43df93d9d6 100644
--- a/Orm/Xtensive.Orm/Core/SimpleScope.cs
+++ b/Orm/Xtensive.Orm/Core/SimpleScope.cs
@@ -4,10 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.27
 
-using System;
 using System.Diagnostics;
 using System.Security;
-using System.Threading;
 
 
 namespace Xtensive.Core
diff --git a/Orm/Xtensive.Orm/Core/SynchronousFutureResult.cs b/Orm/Xtensive.Orm/Core/SynchronousFutureResult.cs
index b517a8cef2..023dd567f1 100644
--- a/Orm/Xtensive.Orm/Core/SynchronousFutureResult.cs
+++ b/Orm/Xtensive.Orm/Core/SynchronousFutureResult.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.12
 
-using System;
-using System.Threading.Tasks;
 
 namespace Xtensive.Core
 {
diff --git a/Orm/Xtensive.Orm/InternalLogs.cs b/Orm/Xtensive.Orm/InternalLogs.cs
index 11dc9ad250..6b471c7f92 100644
--- a/Orm/Xtensive.Orm/InternalLogs.cs
+++ b/Orm/Xtensive.Orm/InternalLogs.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Diagnostics;
 using Xtensive.Orm.Logging;
 using JetBrains.Annotations;
diff --git a/Orm/Xtensive.Orm/IoC/Attributes/ServiceAttribute.cs b/Orm/Xtensive.Orm/IoC/Attributes/ServiceAttribute.cs
index 8298e9f602..a6826e9fac 100644
--- a/Orm/Xtensive.Orm/IoC/Attributes/ServiceAttribute.cs
+++ b/Orm/Xtensive.Orm/IoC/Attributes/ServiceAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
 
 
 namespace Xtensive.IoC
diff --git a/Orm/Xtensive.Orm/IoC/Attributes/ServiceConstructorAttribute.cs b/Orm/Xtensive.Orm/IoC/Attributes/ServiceConstructorAttribute.cs
index bb9cde2208..579cac5dae 100644
--- a/Orm/Xtensive.Orm/IoC/Attributes/ServiceConstructorAttribute.cs
+++ b/Orm/Xtensive.Orm/IoC/Attributes/ServiceConstructorAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
 
 
 namespace Xtensive.IoC
diff --git a/Orm/Xtensive.Orm/IoC/Configuration/ContainerElement.cs b/Orm/Xtensive.Orm/IoC/Configuration/ContainerElement.cs
index bb48be5535..44e13fde1a 100644
--- a/Orm/Xtensive.Orm/IoC/Configuration/ContainerElement.cs
+++ b/Orm/Xtensive.Orm/IoC/Configuration/ContainerElement.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.16
 
-using System;
 using System.Configuration;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/IoC/Configuration/ServiceRegistrationElement.cs b/Orm/Xtensive.Orm/IoC/Configuration/ServiceRegistrationElement.cs
index 1f643baa78..fe6016f718 100644
--- a/Orm/Xtensive.Orm/IoC/Configuration/ServiceRegistrationElement.cs
+++ b/Orm/Xtensive.Orm/IoC/Configuration/ServiceRegistrationElement.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.15
 
-using System;
 using System.Configuration;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/IoC/Interfaces/IServiceContainer.cs b/Orm/Xtensive.Orm/IoC/Interfaces/IServiceContainer.cs
index 6fd4a2bf7a..bf5351046d 100644
--- a/Orm/Xtensive.Orm/IoC/Interfaces/IServiceContainer.cs
+++ b/Orm/Xtensive.Orm/IoC/Interfaces/IServiceContainer.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.IoC
diff --git a/Orm/Xtensive.Orm/IoC/Internals/DefaultServiceContainer.cs b/Orm/Xtensive.Orm/IoC/Internals/DefaultServiceContainer.cs
index a80b9d3614..153c6b76e2 100644
--- a/Orm/Xtensive.Orm/IoC/Internals/DefaultServiceContainer.cs
+++ b/Orm/Xtensive.Orm/IoC/Internals/DefaultServiceContainer.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
-using System.Collections.Generic;
 using System.Collections.Concurrent;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/IoC/Internals/ServiceTypeRegistrationProcessor.cs b/Orm/Xtensive.Orm/IoC/Internals/ServiceTypeRegistrationProcessor.cs
index f67056ee0a..8a18c97d97 100644
--- a/Orm/Xtensive.Orm/IoC/Internals/ServiceTypeRegistrationProcessor.cs
+++ b/Orm/Xtensive.Orm/IoC/Internals/ServiceTypeRegistrationProcessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
 using Xtensive.Collections;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/IoC/ServiceContainer.cs b/Orm/Xtensive.Orm/IoC/ServiceContainer.cs
index 50575b5f06..183fd46ddd 100644
--- a/Orm/Xtensive.Orm/IoC/ServiceContainer.cs
+++ b/Orm/Xtensive.Orm/IoC/ServiceContainer.cs
@@ -4,11 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2009.10.12
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Configuration;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/IoC/ServiceContainerBase.cs b/Orm/Xtensive.Orm/IoC/ServiceContainerBase.cs
index ffe70b4bf9..0424495e13 100644
--- a/Orm/Xtensive.Orm/IoC/ServiceContainerBase.cs
+++ b/Orm/Xtensive.Orm/IoC/ServiceContainerBase.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.01.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/IoC/ServiceRegistration.cs b/Orm/Xtensive.Orm/IoC/ServiceRegistration.cs
index 230b080310..a227241dd8 100644
--- a/Orm/Xtensive.Orm/IoC/ServiceRegistration.cs
+++ b/Orm/Xtensive.Orm/IoC/ServiceRegistration.cs
@@ -4,9 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2009.10.12
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using ServiceRegistrationKey = System.ValueTuple<System.Type, bool>;
diff --git a/Orm/Xtensive.Orm/Linq/ConstantExtractor.cs b/Orm/Xtensive.Orm/Linq/ConstantExtractor.cs
index 732d97268c..b829c514b5 100644
--- a/Orm/Xtensive.Orm/Linq/ConstantExtractor.cs
+++ b/Orm/Xtensive.Orm/Linq/ConstantExtractor.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/ExpressionExtensions.cs b/Orm/Xtensive.Orm/Linq/ExpressionExtensions.cs
index 1b8c31d5e4..b07fae2672 100644
--- a/Orm/Xtensive.Orm/Linq/ExpressionExtensions.cs
+++ b/Orm/Xtensive.Orm/Linq/ExpressionExtensions.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.21
 
-using System;
 using System.Collections.Concurrent;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/ExpressionReplacer.cs b/Orm/Xtensive.Orm/Linq/ExpressionReplacer.cs
index 62fb7723f3..24ab8f2f3e 100644
--- a/Orm/Xtensive.Orm/Linq/ExpressionReplacer.cs
+++ b/Orm/Xtensive.Orm/Linq/ExpressionReplacer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.03.17
 
-using System.Collections.Generic;
 using System.Linq.Expressions;
 
 namespace Xtensive.Linq
diff --git a/Orm/Xtensive.Orm/Linq/ExpressionTree.cs b/Orm/Xtensive.Orm/Linq/ExpressionTree.cs
index 5b8e034646..5183f35574 100644
--- a/Orm/Xtensive.Orm/Linq/ExpressionTree.cs
+++ b/Orm/Xtensive.Orm/Linq/ExpressionTree.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/ExpressionVisitor.cs b/Orm/Xtensive.Orm/Linq/ExpressionVisitor.cs
index 3ec6657269..dd074acbce 100644
--- a/Orm/Xtensive.Orm/Linq/ExpressionVisitor.cs
+++ b/Orm/Xtensive.Orm/Linq/ExpressionVisitor.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.11.11
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq.Expressions;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/ExpressionVisitor{TResult}.cs b/Orm/Xtensive.Orm/Linq/ExpressionVisitor{TResult}.cs
index b9900b549c..eb24a91611 100644
--- a/Orm/Xtensive.Orm/Linq/ExpressionVisitor{TResult}.cs
+++ b/Orm/Xtensive.Orm/Linq/ExpressionVisitor{TResult}.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.09.05
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq.Expressions;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Linq/ExpressionWriter.cs b/Orm/Xtensive.Orm/Linq/ExpressionWriter.cs
index 7b42ebc7f9..59e4939cd2 100644
--- a/Orm/Xtensive.Orm/Linq/ExpressionWriter.cs
+++ b/Orm/Xtensive.Orm/Linq/ExpressionWriter.cs
@@ -4,11 +4,9 @@
 // Created by: Alexey Kochetov
 // Created:    2008.11.25
 
-using System;
 using System.Collections;
 using System.Diagnostics;
 using System.IO;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Runtime.CompilerServices;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/FastExpression.cs b/Orm/Xtensive.Orm/Linq/FastExpression.cs
index 624c71f04e..bc2be51e4c 100644
--- a/Orm/Xtensive.Orm/Linq/FastExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/FastExpression.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 
 namespace Xtensive.Linq
diff --git a/Orm/Xtensive.Orm/Linq/Internals/CachingExpressionCompiler.cs b/Orm/Xtensive.Orm/Linq/Internals/CachingExpressionCompiler.cs
index 6458a33ec2..7787c37d22 100644
--- a/Orm/Xtensive.Orm/Linq/Internals/CachingExpressionCompiler.cs
+++ b/Orm/Xtensive.Orm/Linq/Internals/CachingExpressionCompiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System;
 using System.Collections.Concurrent;
 using System.Linq.Expressions;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/Internals/ExpressionComparer.cs b/Orm/Xtensive.Orm/Linq/Internals/ExpressionComparer.cs
index b5a4aaea0b..24464a764d 100644
--- a/Orm/Xtensive.Orm/Linq/Internals/ExpressionComparer.cs
+++ b/Orm/Xtensive.Orm/Linq/Internals/ExpressionComparer.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Linq/Internals/ExpressionHashCodeCalculator.cs b/Orm/Xtensive.Orm/Linq/Internals/ExpressionHashCodeCalculator.cs
index e1386eae5e..be2d266ffb 100644
--- a/Orm/Xtensive.Orm/Linq/Internals/ExpressionHashCodeCalculator.cs
+++ b/Orm/Xtensive.Orm/Linq/Internals/ExpressionHashCodeCalculator.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Linq/Internals/LambdaExpressionFactory.cs b/Orm/Xtensive.Orm/Linq/Internals/LambdaExpressionFactory.cs
index 2892871f24..db206d8476 100644
--- a/Orm/Xtensive.Orm/Linq/Internals/LambdaExpressionFactory.cs
+++ b/Orm/Xtensive.Orm/Linq/Internals/LambdaExpressionFactory.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.07
 
-using System;
-using System.Collections.Generic;
 using System.Collections.Concurrent;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Linq/Internals/ParameterExpressionRegistry.cs b/Orm/Xtensive.Orm/Linq/Internals/ParameterExpressionRegistry.cs
index 01cce3d0c9..dd5c88ad26 100644
--- a/Orm/Xtensive.Orm/Linq/Internals/ParameterExpressionRegistry.cs
+++ b/Orm/Xtensive.Orm/Linq/Internals/ParameterExpressionRegistry.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.06
 
-using System.Collections.Generic;
 using System.Linq.Expressions;
 
 namespace Xtensive.Linq
diff --git a/Orm/Xtensive.Orm/Linq/QueryableMethodKind.cs b/Orm/Xtensive.Orm/Linq/QueryableMethodKind.cs
index b1d0fd4582..5d56c7e894 100644
--- a/Orm/Xtensive.Orm/Linq/QueryableMethodKind.cs
+++ b/Orm/Xtensive.Orm/Linq/QueryableMethodKind.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.25
 
-using System;
-using System.Linq;
 
 namespace Xtensive.Linq
 {
diff --git a/Orm/Xtensive.Orm/Linq/QueryableVisitor.cs b/Orm/Xtensive.Orm/Linq/QueryableVisitor.cs
index 726077af1b..26a6cd34e5 100644
--- a/Orm/Xtensive.Orm/Linq/QueryableVisitor.cs
+++ b/Orm/Xtensive.Orm/Linq/QueryableVisitor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.25
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ExpressionToSerializableExpressionConverter.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ExpressionToSerializableExpressionConverter.cs
index df87b52d03..acba862e13 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ExpressionToSerializableExpressionConverter.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ExpressionToSerializableExpressionConverter.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kryuchkov
 // Created:    2009.05.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ReflectionExtensions.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ReflectionExtensions.cs
index e10da72981..e0db1dc5c1 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ReflectionExtensions.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/ReflectionExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.02.25
 
-using System;
-using System.Linq;
 using System.Reflection;
 using System.Runtime.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/SerializableExpressionToExpressionConverter.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/SerializableExpressionToExpressionConverter.cs
index 06c5ce318b..3a07472318 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/SerializableExpressionToExpressionConverter.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/Internals/SerializableExpressionToExpressionConverter.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableBinaryExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableBinaryExpression.cs
index cf68689ed5..95190d4e11 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableBinaryExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableBinaryExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConditionalExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConditionalExpression.cs
index 8b2d943090..0b36be52e6 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConditionalExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConditionalExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConstantExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConstantExpression.cs
index 1f41359297..33d153f13f 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConstantExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableConstantExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableDefaultExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableDefaultExpression.cs
index eae7cd156e..7e6f4b51bb 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableDefaultExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableDefaultExpression.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableElementInit.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableElementInit.cs
index dab5d0f28b..82e8f604cf 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableElementInit.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableElementInit.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Kryuchkov
 // Created:    2009.05.14
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableExpression.cs
index 07338c6a3a..3d360dfeb5 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableInvocationExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableInvocationExpression.cs
index 34f485bf6e..eafe4fb792 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableInvocationExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableInvocationExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableLambdaExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableLambdaExpression.cs
index badfb89c13..23f678d0f2 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableLambdaExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableLambdaExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableListInitExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableListInitExpression.cs
index c0a36828de..17f1a8fa63 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableListInitExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableListInitExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberAssignment.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberAssignment.cs
index 43a098252e..8c5aee89e4 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberAssignment.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberAssignment.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.15
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberBinding.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberBinding.cs
index 0011a2f7ac..b77be1f322 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberBinding.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberBinding.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.15
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberExpression.cs
index 685f07be50..12caae3c32 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberInitExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberInitExpression.cs
index 682d6420dd..03895b0dff 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberInitExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberInitExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberListBinding.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberListBinding.cs
index d6c146555a..731c9c7ab4 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberListBinding.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberListBinding.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Kryuchkov
 // Created:    2009.05.15
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberMemberBinding.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberMemberBinding.cs
index edbd19808e..602105c8ee 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberMemberBinding.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMemberMemberBinding.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.15
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMethodCallExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMethodCallExpression.cs
index e5002b074c..945d91bf3a 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMethodCallExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableMethodCallExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewArrayExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewArrayExpression.cs
index 2930e7ec1b..e88cd39f7a 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewArrayExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewArrayExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.13
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewExpression.cs
index 98ba732f52..0a15f1ea63 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableNewExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableParameterExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableParameterExpression.cs
index 69d2d40df8..ae1d531d50 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableParameterExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableParameterExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableTypeBinaryExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableTypeBinaryExpression.cs
index 2ae414725f..ad54661f34 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableTypeBinaryExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableTypeBinaryExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableUnaryExpression.cs b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableUnaryExpression.cs
index 73b403fd97..f4f204dc2a 100644
--- a/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableUnaryExpression.cs
+++ b/Orm/Xtensive.Orm/Linq/SerializableExpressions/SerializableUnaryExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.12
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/ActionHandler.cs b/Orm/Xtensive.Orm/Modelling/Actions/ActionHandler.cs
index 5c6e38ef1f..29e0f15230 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/ActionHandler.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/ActionHandler.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.IoC;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/ActionScope.cs b/Orm/Xtensive.Orm/Modelling/Actions/ActionScope.cs
index 6ec24389bb..c29270160a 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/ActionScope.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/ActionScope.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/ActionSequence.cs b/Orm/Xtensive.Orm/Modelling/Actions/ActionSequence.cs
index 3fc6a70848..e03b477965 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/ActionSequence.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/ActionSequence.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/CreateNodeAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/CreateNodeAction.cs
index 33ed0ae2c0..67dc16b824 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/CreateNodeAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/CreateNodeAction.cs
@@ -4,13 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Collections;
 
-using System.Linq;
 
 namespace Xtensive.Modelling.Actions
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/DataAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/DataAction.cs
index e3e50cdcb7..98c39609d3 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/DataAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/DataAction.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.14
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling.Comparison.Hints;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/GroupingNodeAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/GroupingNodeAction.cs
index a9143563f3..94d8b7325d 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/GroupingNodeAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/GroupingNodeAction.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.22
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Modelling.Actions
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/Interfaces/IActionSequence.cs b/Orm/Xtensive.Orm/Modelling/Actions/Interfaces/IActionSequence.cs
index 9574f151ec..f85db393e8 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/Interfaces/IActionSequence.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/Interfaces/IActionSequence.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Modelling.Actions
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/MoveNodeAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/MoveNodeAction.cs
index 709f717643..9ceb14e40a 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/MoveNodeAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/MoveNodeAction.cs
@@ -4,13 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Collections;
 
-using System.Linq;
 
 namespace Xtensive.Modelling.Actions
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/NodeAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/NodeAction.cs
index a3d79ae76b..b3eba320ce 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/NodeAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/NodeAction.cs
@@ -4,15 +4,12 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Collections;
 using Xtensive.Core;
 
 using Xtensive.Reflection;
 using Xtensive.Modelling.Comparison;
-using System.Linq;
 
 namespace Xtensive.Modelling.Actions
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/NullActionHandler.cs b/Orm/Xtensive.Orm/Modelling/Actions/NullActionHandler.cs
index 9c77e14a0d..cf12962e11 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/NullActionHandler.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/NullActionHandler.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.20
 
-using System;
 
 namespace Xtensive.Modelling.Actions
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/PathNodeReference.cs b/Orm/Xtensive.Orm/Modelling/Actions/PathNodeReference.cs
index d91fb30bae..27a415fdb7 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/PathNodeReference.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/PathNodeReference.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 
 namespace Xtensive.Modelling.Actions
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/PropertyChangeAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/PropertyChangeAction.cs
index b9acdb9754..ef9385493a 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/PropertyChangeAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/PropertyChangeAction.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Actions/RemoveNodeAction.cs b/Orm/Xtensive.Orm/Modelling/Actions/RemoveNodeAction.cs
index 74efa2352a..556fc29bb3 100644
--- a/Orm/Xtensive.Orm/Modelling/Actions/RemoveNodeAction.cs
+++ b/Orm/Xtensive.Orm/Modelling/Actions/RemoveNodeAction.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Attributes/DataDependentAttribute.cs b/Orm/Xtensive.Orm/Modelling/Attributes/DataDependentAttribute.cs
index 24ba4ba498..e7c2448195 100644
--- a/Orm/Xtensive.Orm/Modelling/Attributes/DataDependentAttribute.cs
+++ b/Orm/Xtensive.Orm/Modelling/Attributes/DataDependentAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 
 namespace Xtensive.Modelling.Attributes
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Attributes/PropertyAttribute.cs b/Orm/Xtensive.Orm/Modelling/Attributes/PropertyAttribute.cs
index d6982fe8a5..3c604d98fe 100644
--- a/Orm/Xtensive.Orm/Modelling/Attributes/PropertyAttribute.cs
+++ b/Orm/Xtensive.Orm/Modelling/Attributes/PropertyAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 
 namespace Xtensive.Modelling.Attributes
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Attributes/SystemPropertyAttribute.cs b/Orm/Xtensive.Orm/Modelling/Attributes/SystemPropertyAttribute.cs
index 794299de77..ebd7cda614 100644
--- a/Orm/Xtensive.Orm/Modelling/Attributes/SystemPropertyAttribute.cs
+++ b/Orm/Xtensive.Orm/Modelling/Attributes/SystemPropertyAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/CloningContext.cs b/Orm/Xtensive.Orm/Modelling/CloningContext.cs
index cb8aef7dbe..c452300d47 100644
--- a/Orm/Xtensive.Orm/Modelling/CloningContext.cs
+++ b/Orm/Xtensive.Orm/Modelling/CloningContext.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Comparer.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Comparer.cs
index b32e8da396..80d550f708 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Comparer.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Comparer.cs
@@ -4,11 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.07
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/ComparisonContext.cs b/Orm/Xtensive.Orm/Modelling/Comparison/ComparisonContext.cs
index 7bca36c342..d22555156a 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/ComparisonContext.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/ComparisonContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.16
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Difference.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Difference.cs
index c0f420e996..87a096e523 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Difference.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Difference.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.25
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/CopyDataHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/CopyDataHint.cs
index d171ce4eb6..e58a8eea35 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/CopyDataHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/CopyDataHint.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.30
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DataHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DataHint.cs
index 59cb056637..40d931b3f6 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DataHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DataHint.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.01
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DeleteDataHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DeleteDataHint.cs
index 1afc129a2e..52de317287 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DeleteDataHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/DeleteDataHint.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 
 
 namespace Xtensive.Modelling.Comparison.Hints
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Hint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Hint.cs
index 6cbf03730d..8af9ae2725 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Hint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Hint.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.26
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Modelling.Comparison.Hints
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintSet.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintSet.cs
index ca57611be5..782c5c0640 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintSet.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintSet.cs
@@ -4,13 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.26
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Collections;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Modelling.Comparison.Hints
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintTarget.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintTarget.cs
index 210cb4d28d..0811c92055 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintTarget.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/HintTarget.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.26
 
-using System;
 
 
 namespace Xtensive.Modelling.Comparison.Hints
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IdentityPair.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IdentityPair.cs
index 32e39e89c2..f65eeeffe1 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IdentityPair.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IdentityPair.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.02
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IgnoreHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IgnoreHint.cs
index 6b079cfb9e..86400fc7c5 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IgnoreHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/IgnoreHint.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.28
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHint.cs
index 11ef90ebcc..8cdd7d75c4 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.26
 
-using System.Collections.Generic;
 
 namespace Xtensive.Modelling.Comparison.Hints
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHintSet.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHintSet.cs
index d8d3a4e9d7..7e39f79079 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHintSet.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/Interfaces/IHintSet.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.26
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/RenameHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/RenameHint.cs
index 5de36f2b12..260b9bfbf1 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/RenameHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/RenameHint.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.28
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/UpdateDataHint.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/UpdateDataHint.cs
index 344a949cbe..a9ec9e5e01 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Hints/UpdateDataHint.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Hints/UpdateDataHint.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.30
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IDifference.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IDifference.cs
index 509b173ad5..f962ed2fd8 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IDifference.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IDifference.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.25
 
-using System.Collections.Generic;
 using Xtensive.Modelling.Actions;
 
 namespace Xtensive.Modelling.Comparison
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IHasPropertyChanges.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IHasPropertyChanges.cs
index 00cb710f38..4f32df713d 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IHasPropertyChanges.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IHasPropertyChanges.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.15
 
-using System.Collections.Generic;
 
 namespace Xtensive.Modelling.Comparison
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IUpgrader.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IUpgrader.cs
index 19b6aaa757..458f4c06ab 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IUpgrader.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Interfaces/IUpgrader.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.20
 
-using System.Collections.Generic;
 using Xtensive.Modelling.Actions;
 using Xtensive.Modelling.Comparison.Hints;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/MovementInfo.cs b/Orm/Xtensive.Orm/Modelling/Comparison/MovementInfo.cs
index 58b0cdbafe..b867e0197d 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/MovementInfo.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/MovementInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.25
 
-using System;
 using System.Text;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/NodeCollectionDifference.cs b/Orm/Xtensive.Orm/Modelling/Comparison/NodeCollectionDifference.cs
index cde27ee9ce..1084a0ad6b 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/NodeCollectionDifference.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/NodeCollectionDifference.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.25
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/NodeDifference.cs b/Orm/Xtensive.Orm/Modelling/Comparison/NodeDifference.cs
index a47f8fe559..f8cf7881e4 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/NodeDifference.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/NodeDifference.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.25
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/UpgradeContext.cs b/Orm/Xtensive.Orm/Modelling/Comparison/UpgradeContext.cs
index bc3657a137..025890aeae 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/UpgradeContext.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/UpgradeContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.16
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/Upgrader.cs b/Orm/Xtensive.Orm/Modelling/Comparison/Upgrader.cs
index ac08660c5c..941aa9c452 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/Upgrader.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/Upgrader.cs
@@ -4,11 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.07
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
-using System.Threading;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm/Modelling/Comparison/ValueDifference.cs b/Orm/Xtensive.Orm/Modelling/Comparison/ValueDifference.cs
index 0051af00da..2f5141fce2 100644
--- a/Orm/Xtensive.Orm/Modelling/Comparison/ValueDifference.cs
+++ b/Orm/Xtensive.Orm/Modelling/Comparison/ValueDifference.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Interfaces/IModel.cs b/Orm/Xtensive.Orm/Modelling/Interfaces/IModel.cs
index fa4144401e..941dd02b7f 100644
--- a/Orm/Xtensive.Orm/Modelling/Interfaces/IModel.cs
+++ b/Orm/Xtensive.Orm/Modelling/Interfaces/IModel.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Modelling.Actions;
 
 namespace Xtensive.Modelling
diff --git a/Orm/Xtensive.Orm/Modelling/Interfaces/INesting.cs b/Orm/Xtensive.Orm/Modelling/Interfaces/INesting.cs
index 31622fedd6..975e201f80 100644
--- a/Orm/Xtensive.Orm/Modelling/Interfaces/INesting.cs
+++ b/Orm/Xtensive.Orm/Modelling/Interfaces/INesting.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Reflection;
 
 namespace Xtensive.Modelling
diff --git a/Orm/Xtensive.Orm/Modelling/Interfaces/INode.cs b/Orm/Xtensive.Orm/Modelling/Interfaces/INode.cs
index 5e3eb2aa48..751e007819 100644
--- a/Orm/Xtensive.Orm/Modelling/Interfaces/INode.cs
+++ b/Orm/Xtensive.Orm/Modelling/Interfaces/INode.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.17
 
-using System.Collections.Generic;
 using System.ComponentModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Modelling/Interfaces/INodeCollection{TNode}.cs b/Orm/Xtensive.Orm/Modelling/Interfaces/INodeCollection{TNode}.cs
index 6b449a68b0..513059f8ba 100644
--- a/Orm/Xtensive.Orm/Modelling/Interfaces/INodeCollection{TNode}.cs
+++ b/Orm/Xtensive.Orm/Modelling/Interfaces/INodeCollection{TNode}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System.Collections.Generic;
 using Xtensive.Collections;
 
 namespace Xtensive.Modelling
diff --git a/Orm/Xtensive.Orm/Modelling/Interfaces/IUnorderedNodeCollection.cs b/Orm/Xtensive.Orm/Modelling/Interfaces/IUnorderedNodeCollection.cs
index 56c21a5d06..a7725e6a60 100644
--- a/Orm/Xtensive.Orm/Modelling/Interfaces/IUnorderedNodeCollection.cs
+++ b/Orm/Xtensive.Orm/Modelling/Interfaces/IUnorderedNodeCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Modelling
diff --git a/Orm/Xtensive.Orm/Modelling/Nesting.cs b/Orm/Xtensive.Orm/Modelling/Nesting.cs
index 2f786f9481..48ba68d95f 100644
--- a/Orm/Xtensive.Orm/Modelling/Nesting.cs
+++ b/Orm/Xtensive.Orm/Modelling/Nesting.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Modelling/Nesting{TNode, TParent, TProperty}.cs b/Orm/Xtensive.Orm/Modelling/Nesting{TNode, TParent, TProperty}.cs
index f5aa7687db..ca2615ff64 100644
--- a/Orm/Xtensive.Orm/Modelling/Nesting{TNode, TParent, TProperty}.cs	
+++ b/Orm/Xtensive.Orm/Modelling/Nesting{TNode, TParent, TProperty}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Modelling/Node.cs b/Orm/Xtensive.Orm/Modelling/Node.cs
index 824d6d28f6..cc8bf14d98 100644
--- a/Orm/Xtensive.Orm/Modelling/Node.cs
+++ b/Orm/Xtensive.Orm/Modelling/Node.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.16
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Reflection;
@@ -17,7 +15,6 @@
 
 using Xtensive.Reflection;
 using Xtensive.Modelling.Validation;
-using System.Linq;
 
 namespace Xtensive.Modelling
 {
diff --git a/Orm/Xtensive.Orm/Modelling/NodeCollection.cs b/Orm/Xtensive.Orm/Modelling/NodeCollection.cs
index 68b106b752..425a1f7f7b 100644
--- a/Orm/Xtensive.Orm/Modelling/NodeCollection.cs
+++ b/Orm/Xtensive.Orm/Modelling/NodeCollection.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.16
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Diagnostics;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Modelling/NodeCollection{TNode, TParent, TModel}.cs b/Orm/Xtensive.Orm/Modelling/NodeCollection{TNode, TParent, TModel}.cs
index 23e93bb9a7..f677ff68f4 100644
--- a/Orm/Xtensive.Orm/Modelling/NodeCollection{TNode, TParent, TModel}.cs	
+++ b/Orm/Xtensive.Orm/Modelling/NodeCollection{TNode, TParent, TModel}.cs	
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.20
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 namespace Xtensive.Modelling
diff --git a/Orm/Xtensive.Orm/Modelling/Node{TParent, TModel}.cs b/Orm/Xtensive.Orm/Modelling/Node{TParent, TModel}.cs
index e81bdc3b52..728f5951ee 100644
--- a/Orm/Xtensive.Orm/Modelling/Node{TParent, TModel}.cs	
+++ b/Orm/Xtensive.Orm/Modelling/Node{TParent, TModel}.cs	
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.16
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Modelling/PathNodeExtensions.cs b/Orm/Xtensive.Orm/Modelling/PathNodeExtensions.cs
index f44479c852..8e66e3cfe5 100644
--- a/Orm/Xtensive.Orm/Modelling/PathNodeExtensions.cs
+++ b/Orm/Xtensive.Orm/Modelling/PathNodeExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.05
 
-using System;
 using System.Diagnostics;
 
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Modelling/PropertyAccessor.cs b/Orm/Xtensive.Orm/Modelling/PropertyAccessor.cs
index 909ebf3480..6a178443d2 100644
--- a/Orm/Xtensive.Orm/Modelling/PropertyAccessor.cs
+++ b/Orm/Xtensive.Orm/Modelling/PropertyAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.18
 
-using System;
 using System.Reflection;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Modelling/PropertyAccessorDictionary.cs b/Orm/Xtensive.Orm/Modelling/PropertyAccessorDictionary.cs
index 8e0d646394..a9bc4114b8 100644
--- a/Orm/Xtensive.Orm/Modelling/PropertyAccessorDictionary.cs
+++ b/Orm/Xtensive.Orm/Modelling/PropertyAccessorDictionary.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.01
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 
 namespace Xtensive.Modelling
 {
diff --git a/Orm/Xtensive.Orm/Modelling/Validation/ValidationContext.cs b/Orm/Xtensive.Orm/Modelling/Validation/ValidationContext.cs
index 2f51f66df2..803b2064d8 100644
--- a/Orm/Xtensive.Orm/Modelling/Validation/ValidationContext.cs
+++ b/Orm/Xtensive.Orm/Modelling/Validation/ValidationContext.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.03.23
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/AssociationAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/AssociationAttribute.cs
index 2332e4da47..281c7446d0 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/AssociationAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/AssociationAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.07
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/CompilerAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/CompilerAttribute.cs
index 28eee111f9..ce24a58f4f 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/CompilerAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/CompilerAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.09
 
-using System;
 using JetBrains.Annotations;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/CompilerContainerAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/CompilerContainerAttribute.cs
index 9430593fdb..e25bc4db7d 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/CompilerContainerAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/CompilerContainerAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.03.30
 
-using System;
 using JetBrains.Annotations;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/FieldAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/FieldAttribute.cs
index e6ec16bfb2..a8def39cc2 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/FieldAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/FieldAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.04
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/FieldMappingAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/FieldMappingAttribute.cs
index 28e0ed91f4..5322b85f1d 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/FieldMappingAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/FieldMappingAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.07.10
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/FullTextAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/FullTextAttribute.cs
index c348cdaa3f..51e3ddf3c6 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/FullTextAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/FullTextAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.14
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/HierarchyRootAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/HierarchyRootAttribute.cs
index 0499da40fc..d5408b37d2 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/HierarchyRootAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/HierarchyRootAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.11
 
-using System;
 using JetBrains.Annotations;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/IndexAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/IndexAttribute.cs
index cc60ba07ee..742356327c 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/IndexAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/IndexAttribute.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/KeyAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/KeyAttribute.cs
index 75373077e5..796ed317b1 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/KeyAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/KeyAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.26
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorAttribute.cs
index 92adb8eda5..c8b437ded0 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.26
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/MaterializedViewAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/MaterializedViewAttribute.cs
index 2ca7dd548b..611a33d627 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/MaterializedViewAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/MaterializedViewAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.12.28
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/StorageAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/StorageAttribute.cs
index 168b586543..94296e61b2 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/StorageAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/StorageAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.11
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/SystemTypeAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/SystemTypeAttribute.cs
index 327300f48d..7a8e2965b3 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/SystemTypeAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/SystemTypeAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.12.24
 
-using System;
 
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/TableMappingAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/TableMappingAttribute.cs
index d977b6773d..65a6032bb4 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/TableMappingAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/TableMappingAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.04
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/TypeAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/TypeAttribute.cs
index b382a6109b..a4afe11606 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/TypeAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/TypeAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.09
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorAttribute.cs
index 2b37aabed7..beeabca599 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.08.13
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorValueAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorValueAttribute.cs
index 1bcbee06e6..6fcd8b6906 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorValueAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/TypeDiscriminatorValueAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.25
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/VersionAttribute.cs b/Orm/Xtensive.Orm/Orm/Attributes/VersionAttribute.cs
index 4e1dea0dbd..4a24f0ef33 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/VersionAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/VersionAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.08.13
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Attributes/VersionMode.cs b/Orm/Xtensive.Orm/Orm/Attributes/VersionMode.cs
index edaa0c8fcf..2643fa148b 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/VersionMode.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/VersionMode.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.08.04
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/AssociationBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/AssociationBuilder.cs
index db882628e5..a2b972c527 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/AssociationBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/AssociationBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.03
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/AttributeProcessor.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/AttributeProcessor.cs
index 645331f053..379e838ab5 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/AttributeProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/AttributeProcessor.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.25
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/AutoGenericCombinator.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/AutoGenericCombinator.cs
index 85e69ee923..136c572c9f 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/AutoGenericCombinator.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/AutoGenericCombinator.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Building.Builders
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/DatabaseDependencyBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/DatabaseDependencyBuilder.cs
index 010e3cf277..b6220d7083 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/DatabaseDependencyBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/DatabaseDependencyBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilder.cs
index 74cd2ddbb7..4d56eddf74 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.03
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilderConfiguration.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilderConfiguration.cs
index 129ec03d9b..c91835cee8 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilderConfiguration.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/DomainBuilderConfiguration.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.05.01
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IModelFilter.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IModelFilter.cs
index 735a3622ed..00bdc57623 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IModelFilter.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IModelFilter.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.14
 
-using System;
 using System.Reflection;
 
 namespace Xtensive.Orm.Building.Builders
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/ITypeIdProvider.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/ITypeIdProvider.cs
index f136a978cb..2e6e7f8f43 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/ITypeIdProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/ITypeIdProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.19
 
-using System;
 
 namespace Xtensive.Orm.Building.Builders
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClassTable.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClassTable.cs
index b88dde496c..7cf30b01fb 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClassTable.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClassTable.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.17
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClusteredIndexes.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClusteredIndexes.cs
index 7e4590c27c..ff001f72e6 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClusteredIndexes.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ClusteredIndexes.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.25
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ConcreteTable.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ConcreteTable.cs
index 47442faec5..e23dd98291 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ConcreteTable.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.ConcreteTable.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.17
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.FullText.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.FullText.cs
index 6c54868219..617882ad04 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.FullText.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.FullText.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.SingleTable.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.SingleTable.cs
index 13f6f2500f..bc7fb59045 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.SingleTable.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.SingleTable.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.17
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.cs
index 67d82ab66a..7e3fab99d4 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/IndexBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.10.02
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/KeyGeneratorFactory.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/KeyGeneratorFactory.cs
index c89790813d..be76723dd5 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/KeyGeneratorFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/KeyGeneratorFactory.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.IoC;
 using Xtensive.Orm.Internals.KeyGenerators;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/MemberCompilerProviderBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/MemberCompilerProviderBuilder.cs
index 910dddd047..c5a4a8715b 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/MemberCompilerProviderBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/MemberCompilerProviderBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/ModelBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/ModelBuilder.cs
index 3c6050ea40..da4b76af39 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/ModelBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/ModelBuilder.cs
@@ -4,10 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.26
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Building.DependencyGraph;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/ModelDefBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/ModelDefBuilder.cs
index b89640ad4c..3d9e0d9988 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/ModelDefBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/ModelDefBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/ModelMappingBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/ModelMappingBuilder.cs
index cbd2ada86e..d3e12150f1 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/ModelMappingBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/ModelMappingBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.06
 
-using System;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/PartialIndexFilterBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/PartialIndexFilterBuilder.cs
index f8ecf94d25..e02adf5611 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/PartialIndexFilterBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/PartialIndexFilterBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.07
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/ProviderDescriptor.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/ProviderDescriptor.cs
index 01d59339a5..81cbc21c25 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/ProviderDescriptor.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/ProviderDescriptor.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.01
 
-using System;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingBuilder.cs
index 9ad2d578e5..e7d74ec557 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Orm.Logging;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingValidator.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingValidator.cs
index 57e79afdfd..dad0b235c7 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/StorageMappingValidator.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/TypeBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/TypeBuilder.cs
index 0db467dc80..506c80df2f 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/TypeBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/TypeBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.10.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/TypeIdBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/TypeIdBuilder.cs
index 032815ebec..bcb664efcf 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/TypeIdBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/TypeIdBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.14
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Builders/ValueTypeBuilder.cs b/Orm/Xtensive.Orm/Orm/Building/Builders/ValueTypeBuilder.cs
index b2775bf24a..31c6103abe 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Builders/ValueTypeBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Builders/ValueTypeBuilder.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.27
 
-using System;
 using Xtensive.Reflection;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Building/BuildingContext.cs b/Orm/Xtensive.Orm/Orm/Building/BuildingContext.cs
index e911e81c5c..9564ccc3a7 100644
--- a/Orm/Xtensive.Orm/Orm/Building/BuildingContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/BuildingContext.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.03
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Building.Definitions;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/DomainModelDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/DomainModelDef.cs
index f3c20abc14..91629d13c9 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/DomainModelDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/DomainModelDef.cs
@@ -4,15 +4,12 @@
 // Created by: Alex Ustinov
 // Created:    2007.07.11
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Model;
 
-using System.Linq;
 
 namespace Xtensive.Orm.Building.Definitions
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/FieldDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/FieldDef.cs
index 3fb5d381fd..e9272e58e0 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/FieldDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/FieldDef.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.10
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextFieldDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextFieldDef.cs
index 6addafb995..1d196e3f7b 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextFieldDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextFieldDef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.18
 
-using System;
 using System.Diagnostics;
 
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDef.cs
index b00088b151..aee2167918 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDef.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.21
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDefCollection.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDefCollection.cs
index 83039a4964..5cbc271852 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/FullTextIndexDefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.21
 
-using System;
 using System.Diagnostics;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDef.cs
index fe0ce9dfb8..a485c9652c 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDef.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.11
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDefCollection.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDefCollection.cs
index 44393df996..d3e48534e2 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/HierarchyDefCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.11
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/IndexDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/IndexDef.cs
index dc4e5656ae..24cf2a0acd 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/IndexDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/IndexDef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2007.09.29
 
-using System;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
 using System.Linq.Expressions;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDef.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDef.cs
index b53e13c8ba..0a2a411a33 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDef.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDef.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.27
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDefCollection.cs b/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDefCollection.cs
index 4d09822e96..aae41e6e7f 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Definitions/TypeDefCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Edge.cs b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Edge.cs
index 530e76fc4f..81e508e9e0 100644
--- a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Edge.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Edge.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.02.24
 
-using System;
 
 namespace Xtensive.Orm.Building.DependencyGraph
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeKind.cs b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeKind.cs
index 7b5797dd55..d4414b2bd0 100644
--- a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeKind.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeKind.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.02.24
 
-using System;
 
 namespace Xtensive.Orm.Building.DependencyGraph
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeWeight.cs b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeWeight.cs
index b0b36f33bf..7c64daf57b 100644
--- a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeWeight.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/EdgeWeight.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.20
 
-using System;
 
 namespace Xtensive.Orm.Building.DependencyGraph
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Graph.cs b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Graph.cs
index 64f3665322..0f1a85b8ee 100644
--- a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Graph.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Graph.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.12
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Building.DependencyGraph
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Node.cs b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Node.cs
index dffe663e6a..a8cd9d3575 100644
--- a/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Node.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/DependencyGraph/Node.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.12
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Building.DependencyGraph
 {
diff --git a/Orm/Xtensive.Orm/Orm/Building/FixupActionProcessor.cs b/Orm/Xtensive.Orm/Orm/Building/FixupActionProcessor.cs
index 9de81fbf6b..3fe48f4e8e 100644
--- a/Orm/Xtensive.Orm/Orm/Building/FixupActionProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/FixupActionProcessor.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Building.DependencyGraph;
diff --git a/Orm/Xtensive.Orm/Orm/Building/FixupActions/MakeTypeNonAbstractAction.cs b/Orm/Xtensive.Orm/Orm/Building/FixupActions/MakeTypeNonAbstractAction.cs
index 2414e810d9..6db0a2e12b 100644
--- a/Orm/Xtensive.Orm/Orm/Building/FixupActions/MakeTypeNonAbstractAction.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/FixupActions/MakeTypeNonAbstractAction.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.09.08
 
-using System;
 using Xtensive.Orm.Building.Definitions;
 
 namespace Xtensive.Orm.Building.FixupActions
diff --git a/Orm/Xtensive.Orm/Orm/Building/ModelInspectionResult.cs b/Orm/Xtensive.Orm/Orm/Building/ModelInspectionResult.cs
index e9b21385b6..3c13cd34db 100644
--- a/Orm/Xtensive.Orm/Orm/Building/ModelInspectionResult.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/ModelInspectionResult.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.05.28
 
-using System.Collections.Generic;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Building.FixupActions;
 
diff --git a/Orm/Xtensive.Orm/Orm/Building/ModelInspector.cs b/Orm/Xtensive.Orm/Orm/Building/ModelInspector.cs
index f559958b1f..e1f17c552b 100644
--- a/Orm/Xtensive.Orm/Orm/Building/ModelInspector.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/ModelInspector.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.02.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Reflection;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Building.DependencyGraph;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Module.cs b/Orm/Xtensive.Orm/Orm/Building/Module.cs
index 93caa0b1b6..47217ba140 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Module.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Module.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.09.27
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Building.Definitions;
 
 namespace Xtensive.Orm.Building
diff --git a/Orm/Xtensive.Orm/Orm/Building/PrefetchActionContainer.cs b/Orm/Xtensive.Orm/Orm/Building/PrefetchActionContainer.cs
index cd69a075d9..75234b7dbc 100644
--- a/Orm/Xtensive.Orm/Orm/Building/PrefetchActionContainer.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/PrefetchActionContainer.cs
@@ -4,10 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.27
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Internals.Prefetch;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Building/SystemModule.cs b/Orm/Xtensive.Orm/Orm/Building/SystemModule.cs
index d50782ea6d..0c8dc95ade 100644
--- a/Orm/Xtensive.Orm/Orm/Building/SystemModule.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/SystemModule.cs
@@ -4,8 +4,6 @@
 // Created by: Andrey Turkov
 // Created:    2013.08.21
 
-using System;
-using System.Linq;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Metadata;
diff --git a/Orm/Xtensive.Orm/Orm/Building/Validator.cs b/Orm/Xtensive.Orm/Orm/Building/Validator.cs
index e67c402420..e80f37b2c0 100644
--- a/Orm/Xtensive.Orm/Orm/Building/Validator.cs
+++ b/Orm/Xtensive.Orm/Orm/Building/Validator.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.12
 
-using System;
-using System.Collections.Generic;
 using System.Text.RegularExpressions;
 using Xtensive.Orm.Building.Definitions;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/CommandProcessorContextProvider.cs b/Orm/Xtensive.Orm/Orm/CommandProcessorContextProvider.cs
index 10d8b619b6..b7888d6c2f 100644
--- a/Orm/Xtensive.Orm/Orm/CommandProcessorContextProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/CommandProcessorContextProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.07.12
 
-using System;
 using System.Collections.Concurrent;
 using Xtensive.Orm.Providers;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/ConfigurationBase.cs b/Orm/Xtensive.Orm/Orm/Configuration/ConfigurationBase.cs
index 30aed0ce16..d1647aa116 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/ConfigurationBase.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/ConfigurationBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.02.22
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/DatabaseConfigurationCollection.cs b/Orm/Xtensive.Orm/Orm/Configuration/DatabaseConfigurationCollection.cs
index b7b469f7ae..8610a08b1e 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/DatabaseConfigurationCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/DatabaseConfigurationCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.08
 
-using System;
 using Xtensive.Collections;
 
 namespace Xtensive.Orm.Configuration
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/DomainConfiguration.cs b/Orm/Xtensive.Orm/Orm/Configuration/DomainConfiguration.cs
index 2596f753e7..24328d045b 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/DomainConfiguration.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/DomainConfiguration.cs
@@ -4,9 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.03
 
-using System;
 using System.Configuration;
-using System.Linq;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration.Elements;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/DomainOptions.cs b/Orm/Xtensive.Orm/Orm/Configuration/DomainOptions.cs
index 3bcae2e322..af211ea171 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/DomainOptions.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/DomainOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.12
 
-using System;
 
 namespace Xtensive.Orm.Configuration
 {
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/DomainTypeRegistry.cs b/Orm/Xtensive.Orm/Orm/Configuration/DomainTypeRegistry.cs
index 803720f5b9..9b6bfce4f3 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/DomainTypeRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/DomainTypeRegistry.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.03
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
-using System.Linq;
 using Xtensive.IoC;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Upgrade;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Elements/DomainConfigurationElement.cs b/Orm/Xtensive.Orm/Orm/Configuration/Elements/DomainConfigurationElement.cs
index 1d7131a5d2..07cc9ea2c0 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Elements/DomainConfigurationElement.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Elements/DomainConfigurationElement.cs
@@ -4,7 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.08.11
 
-using System;
 using System.Configuration;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Elements/IgnoreRuleElement.cs b/Orm/Xtensive.Orm/Orm/Configuration/Elements/IgnoreRuleElement.cs
index 583c2f1bb8..5cdd40f07c 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Elements/IgnoreRuleElement.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Elements/IgnoreRuleElement.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.16
 
-using System;
 using System.Configuration;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Elements/NamingConventionElement.cs b/Orm/Xtensive.Orm/Orm/Configuration/Elements/NamingConventionElement.cs
index 4e891a8f42..e5289190f4 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Elements/NamingConventionElement.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Elements/NamingConventionElement.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.08.07
 
-using System;
 using System.Configuration;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Elements/SessionConfigurationElement.cs b/Orm/Xtensive.Orm/Orm/Configuration/Elements/SessionConfigurationElement.cs
index 3bab8025ec..61608720d2 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Elements/SessionConfigurationElement.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Elements/SessionConfigurationElement.cs
@@ -4,7 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.08.11
 
-using System;
 using System.Configuration;
 using System.IO;
 using System.Transactions;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Elements/VersioningConventionElement.cs b/Orm/Xtensive.Orm/Orm/Configuration/Elements/VersioningConventionElement.cs
index 7cb63e06c3..a94cd8eb0c 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Elements/VersioningConventionElement.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Elements/VersioningConventionElement.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.03.14
 
-using System;
 using System.Configuration;
 
 namespace Xtensive.Orm.Configuration.Elements
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRule.cs b/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRule.cs
index dd8c53c2a7..b9495dbe36 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRule.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRule.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.16
 
-using System;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRuleCollection.cs b/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRuleCollection.cs
index 4d86989212..e4f426747d 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRuleCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/IgnoreRuleCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.16
 
-using System;
 using Xtensive.Collections;
 
 namespace Xtensive.Orm.Configuration
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Internals/ConnectionInfoParser.cs b/Orm/Xtensive.Orm/Orm/Configuration/Internals/ConnectionInfoParser.cs
index 452d684ab9..fa1ee11313 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Internals/ConnectionInfoParser.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Internals/ConnectionInfoParser.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.27
 
-using System;
 using System.Configuration;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Internals/DomainTypeRegistrationHandler.cs b/Orm/Xtensive.Orm/Orm/Configuration/Internals/DomainTypeRegistrationHandler.cs
index 388e369d6e..712f47bc48 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Internals/DomainTypeRegistrationHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Internals/DomainTypeRegistrationHandler.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.21
 
-using System;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Internals/MappingRuleConstructionFlow.cs b/Orm/Xtensive.Orm/Orm/Configuration/Internals/MappingRuleConstructionFlow.cs
index c4df884d1e..1a1eb65205 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Internals/MappingRuleConstructionFlow.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Internals/MappingRuleConstructionFlow.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.08
 
-using System.Collections.Generic;
 using System.Reflection;
 
 namespace Xtensive.Orm.Configuration
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/Internals/NodeConfigurationExtensions.cs b/Orm/Xtensive.Orm/Orm/Configuration/Internals/NodeConfigurationExtensions.cs
index 6b19db78db..42bc38859b 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/Internals/NodeConfigurationExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/Internals/NodeConfigurationExtensions.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/KeyGeneratorConfigurationCollection.cs b/Orm/Xtensive.Orm/Orm/Configuration/KeyGeneratorConfigurationCollection.cs
index faa0f1234d..d2ecb734c5 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/KeyGeneratorConfigurationCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/KeyGeneratorConfigurationCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.28
 
-using System;
 using Xtensive.Collections;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/LetterCasePolicy.cs b/Orm/Xtensive.Orm/Orm/Configuration/LetterCasePolicy.cs
index b8c3757da0..f23ed7bace 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/LetterCasePolicy.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/LetterCasePolicy.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.04
 
-using System;
 
 namespace Xtensive.Orm.Configuration
 {
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistration.cs b/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistration.cs
index 35330064d2..a93ca53531 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistration.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistration.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.27
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistry.cs b/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistry.cs
index 1c4d27c8d5..fa82a81be3 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/LinqExtensionRegistry.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.27
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/LoggingConfiguration.cs b/Orm/Xtensive.Orm/Orm/Configuration/LoggingConfiguration.cs
index 8975e4e86f..6bd55aa911 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/LoggingConfiguration.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/LoggingConfiguration.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.27
 
-using System;
-using System.Collections.Generic;
 using System.Configuration;
 using Xtensive.Core;
 using ConfigurationSection = Xtensive.Orm.Configuration.Elements.ConfigurationSection;
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/MappingRuleCollection.cs b/Orm/Xtensive.Orm/Orm/Configuration/MappingRuleCollection.cs
index a347ad7832..65f7a15f54 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/MappingRuleCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/MappingRuleCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.07
 
-using System;
 using System.Reflection;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/NameMappingCollection.cs b/Orm/Xtensive.Orm/Orm/Configuration/NameMappingCollection.cs
index 12569674db..2d4b5cd2b6 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/NameMappingCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/NameMappingCollection.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using JetBrains.Annotations;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/NamespacePolicy.cs b/Orm/Xtensive.Orm/Orm/Configuration/NamespacePolicy.cs
index d05d6a9d5b..738055f823 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/NamespacePolicy.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/NamespacePolicy.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.04
 
-using System;
 
 namespace Xtensive.Orm.Configuration
 {
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/NamingConvention.cs b/Orm/Xtensive.Orm/Orm/Configuration/NamingConvention.cs
index 461b274273..ddec8df599 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/NamingConvention.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/NamingConvention.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.04
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/NamingRules.cs b/Orm/Xtensive.Orm/Orm/Configuration/NamingRules.cs
index b7e3651ed1..c2c6c3e902 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/NamingRules.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/NamingRules.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.04
 
-using System;
 
 namespace Xtensive.Orm.Configuration
 {
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/NodeConfiguration.cs b/Orm/Xtensive.Orm/Orm/Configuration/NodeConfiguration.cs
index e18509b4d0..21b18797b3 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/NodeConfiguration.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/NodeConfiguration.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Configuration
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/ReaderPreloadingPolicy.cs b/Orm/Xtensive.Orm/Orm/Configuration/ReaderPreloadingPolicy.cs
index d8057d9f15..4d2eaf9d9e 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/ReaderPreloadingPolicy.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/ReaderPreloadingPolicy.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.02
 
-using System;
 
 namespace Xtensive.Orm.Configuration
 {
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/SessionConfiguration.cs b/Orm/Xtensive.Orm/Orm/Configuration/SessionConfiguration.cs
index 1107f23c39..000e454928 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/SessionConfiguration.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/SessionConfiguration.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.29
 
-using System;
 using System.Transactions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/SessionConfigurationCollection.cs b/Orm/Xtensive.Orm/Orm/Configuration/SessionConfigurationCollection.cs
index 42db6d4703..8fe52b18cb 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/SessionConfigurationCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/SessionConfigurationCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.12.05
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/SessionOptions.cs b/Orm/Xtensive.Orm/Orm/Configuration/SessionOptions.cs
index 1fd1a6d496..c0ecb6f7de 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/SessionOptions.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/SessionOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.10.06
 
-using System;
 using JetBrains.Annotations;
 
 namespace Xtensive.Orm.Configuration
diff --git a/Orm/Xtensive.Orm/Orm/Configuration/VersioningConvention.cs b/Orm/Xtensive.Orm/Orm/Configuration/VersioningConvention.cs
index 6217c87f4c..a77538d416 100644
--- a/Orm/Xtensive.Orm/Orm/Configuration/VersioningConvention.cs
+++ b/Orm/Xtensive.Orm/Orm/Configuration/VersioningConvention.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.03.03
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Configuration
diff --git a/Orm/Xtensive.Orm/Orm/ConnectionErrorEventData.cs b/Orm/Xtensive.Orm/Orm/ConnectionErrorEventData.cs
index 1e8ff71210..29f11807db 100644
--- a/Orm/Xtensive.Orm/Orm/ConnectionErrorEventData.cs
+++ b/Orm/Xtensive.Orm/Orm/ConnectionErrorEventData.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data.Common;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/ConnectionInfo.cs b/Orm/Xtensive.Orm/Orm/ConnectionInfo.cs
index e0ccc97652..6dca712192 100644
--- a/Orm/Xtensive.Orm/Orm/ConnectionInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/ConnectionInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.17
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/DbCommandEventArgs.cs b/Orm/Xtensive.Orm/Orm/DbCommandEventArgs.cs
index c94355a27d..c1d87b4d92 100644
--- a/Orm/Xtensive.Orm/Orm/DbCommandEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/DbCommandEventArgs.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Linq;
 using System.Text;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/DelayedQuery.cs b/Orm/Xtensive.Orm/Orm/DelayedQuery.cs
index b77e2db2c4..f9e6c7dc9d 100644
--- a/Orm/Xtensive.Orm/Orm/DelayedQuery.cs
+++ b/Orm/Xtensive.Orm/Orm/DelayedQuery.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.19
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Linq.Materialization;
diff --git a/Orm/Xtensive.Orm/Orm/DelayedQuery{T}.cs b/Orm/Xtensive.Orm/Orm/DelayedQuery{T}.cs
index f800ba3f73..9ce2be48e4 100644
--- a/Orm/Xtensive.Orm/Orm/DelayedQuery{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/DelayedQuery{T}.cs
@@ -4,11 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.19
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/DelayedScalarQuery{T}.cs b/Orm/Xtensive.Orm/Orm/DelayedScalarQuery{T}.cs
index e4e4fe7b5a..b1f3b3fcaf 100644
--- a/Orm/Xtensive.Orm/Orm/DelayedScalarQuery{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/DelayedScalarQuery{T}.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.19
 
-using System;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Domain.cs b/Orm/Xtensive.Orm/Orm/Domain.cs
index 3da42b0a9e..914c340553 100644
--- a/Orm/Xtensive.Orm/Orm/Domain.cs
+++ b/Orm/Xtensive.Orm/Orm/Domain.cs
@@ -4,12 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.03
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Runtime.ExceptionServices;
-using System.Threading;
-using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Xtensive.Caching;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/DomainBound.cs b/Orm/Xtensive.Orm/Orm/DomainBound.cs
index da0b8a8710..7a1cfb1648 100644
--- a/Orm/Xtensive.Orm/Orm/DomainBound.cs
+++ b/Orm/Xtensive.Orm/Orm/DomainBound.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.10
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Orm/DomainUpgradeMode.cs b/Orm/Xtensive.Orm/Orm/DomainUpgradeMode.cs
index f99b4375a9..cfafad971c 100644
--- a/Orm/Xtensive.Orm/Orm/DomainUpgradeMode.cs
+++ b/Orm/Xtensive.Orm/Orm/DomainUpgradeMode.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.06
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Entity.cs b/Orm/Xtensive.Orm/Orm/Entity.cs
index 1d53636234..ba90f0716f 100644
--- a/Orm/Xtensive.Orm/Orm/Entity.cs
+++ b/Orm/Xtensive.Orm/Orm/Entity.cs
@@ -4,11 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.01
 
-using System;
-using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Caching;
diff --git a/Orm/Xtensive.Orm/Orm/EntityEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntityEventArgs.cs
index 5e00fac04b..7352ec48eb 100644
--- a/Orm/Xtensive.Orm/Orm/EntityEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.04
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/EntityEventBroker.cs b/Orm/Xtensive.Orm/Orm/EntityEventBroker.cs
index 8c53137a73..bb04d2cae9 100644
--- a/Orm/Xtensive.Orm/Orm/EntityEventBroker.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityEventBroker.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.29
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/EntityFieldValueGetCompletedEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntityFieldValueGetCompletedEventArgs.cs
index 5a95931fdb..eedfa58f3c 100644
--- a/Orm/Xtensive.Orm/Orm/EntityFieldValueGetCompletedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityFieldValueGetCompletedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/EntityFieldValueSetCompletedEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntityFieldValueSetCompletedEventArgs.cs
index bcd1f1aa59..e837ff2020 100644
--- a/Orm/Xtensive.Orm/Orm/EntityFieldValueSetCompletedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityFieldValueSetCompletedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/EntityRemoveCompletedEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntityRemoveCompletedEventArgs.cs
index f7d8f0d40e..ea621547a6 100644
--- a/Orm/Xtensive.Orm/Orm/EntityRemoveCompletedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityRemoveCompletedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/EntityRemoveReason.cs b/Orm/Xtensive.Orm/Orm/EntityRemoveReason.cs
index 0c06ca215a..cc0b5ec4f4 100644
--- a/Orm/Xtensive.Orm/Orm/EntityRemoveReason.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityRemoveReason.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.10.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/EntityRemovingEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntityRemovingEventArgs.cs
index 65f52bd178..c1aaf4c935 100644
--- a/Orm/Xtensive.Orm/Orm/EntityRemovingEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityRemovingEventArgs.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Kudelin
 // Created:    2018.10.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/EntitySetActionCompletedEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntitySetActionCompletedEventArgs.cs
index 6d0512e516..c04c929b04 100644
--- a/Orm/Xtensive.Orm/Orm/EntitySetActionCompletedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntitySetActionCompletedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.23
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/EntitySetBase.cs b/Orm/Xtensive.Orm/Orm/EntitySetBase.cs
index 72bd04e79a..8f9014241d 100644
--- a/Orm/Xtensive.Orm/Orm/EntitySetBase.cs
+++ b/Orm/Xtensive.Orm/Orm/EntitySetBase.cs
@@ -4,11 +4,8 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.09.10
 
-using System;
-using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.ComponentModel;
-using System.Linq;
 using System.Runtime.Serialization;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/EntitySetEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntitySetEventArgs.cs
index 23a49acd65..aefd42cc2a 100644
--- a/Orm/Xtensive.Orm/Orm/EntitySetEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntitySetEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.23
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/EntitySetItemActionCompletedEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntitySetItemActionCompletedEventArgs.cs
index b482fd4420..61656771a8 100644
--- a/Orm/Xtensive.Orm/Orm/EntitySetItemActionCompletedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntitySetItemActionCompletedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.23
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/EntitySetItemEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntitySetItemEventArgs.cs
index 69279686fd..5079415ec1 100644
--- a/Orm/Xtensive.Orm/Orm/EntitySetItemEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntitySetItemEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.23
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/EntitySet{T}.cs b/Orm/Xtensive.Orm/Orm/EntitySet{T}.cs
index 38b3df05b7..e4d58d68f4 100644
--- a/Orm/Xtensive.Orm/Orm/EntitySet{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/EntitySet{T}.cs
@@ -4,11 +4,8 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.09.10
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Runtime.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/EntityState.cs b/Orm/Xtensive.Orm/Orm/EntityState.cs
index 6c83167a45..b4544c1177 100644
--- a/Orm/Xtensive.Orm/Orm/EntityState.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityState.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.07
 
-using System;
 using System.Diagnostics;
 using Xtensive.Caching;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/EntityVersionInfoChangedEventArgs.cs b/Orm/Xtensive.Orm/Orm/EntityVersionInfoChangedEventArgs.cs
index 6f12559d81..6818713ada 100644
--- a/Orm/Xtensive.Orm/Orm/EntityVersionInfoChangedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/EntityVersionInfoChangedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/CheckConstraintViolationException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/CheckConstraintViolationException.cs
index ce31836f86..cfcd590e52 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/CheckConstraintViolationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/CheckConstraintViolationException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/ConnectionErrorException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/ConnectionErrorException.cs
index fbd20ed55a..d71b189c3e 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/ConnectionErrorException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/ConnectionErrorException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/ConstraintViolationException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/ConstraintViolationException.cs
index a9cc643374..6bc31e90a6 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/ConstraintViolationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/ConstraintViolationException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/DeadlockException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/DeadlockException.cs
index d6a2f139e5..4e09839715 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/DeadlockException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/DeadlockException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/DomainBuilderException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/DomainBuilderException.cs
index 9914d961bb..4e1ef63127 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/DomainBuilderException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/DomainBuilderException.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.18
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/OperationTimeoutException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/OperationTimeoutException.cs
index 54c0c353fc..05a977b261 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/OperationTimeoutException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/OperationTimeoutException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.09
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/ParametersLimitExceededException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/ParametersLimitExceededException.cs
index bdd886c412..fc6baa97c2 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/ParametersLimitExceededException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/ParametersLimitExceededException.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2018.11.02
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/QueryTranslationException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/QueryTranslationException.cs
index d41df25d79..500c09cc45 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/QueryTranslationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/QueryTranslationException.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.07
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialConstraintViolationException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialConstraintViolationException.cs
index 4575034b4c..88197be607 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialConstraintViolationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialConstraintViolationException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialIntegrityException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialIntegrityException.cs
index 12c3a10e89..fb693dbc3b 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialIntegrityException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/ReferentialIntegrityException.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.01
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/ReprocessableException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/ReprocessableException.cs
index eaf24ee309..777b93c2db 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/ReprocessableException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/ReprocessableException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.17
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/SchemaSynchronizationException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/SchemaSynchronizationException.cs
index e99948ba29..a4771283ed 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/SchemaSynchronizationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/SchemaSynchronizationException.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.18
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/StorageException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/StorageException.cs
index b877594220..4e3a06f85f 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/StorageException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/StorageException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.17
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/StorageExceptionInfo.cs b/Orm/Xtensive.Orm/Orm/Exceptions/StorageExceptionInfo.cs
index 4879b0d990..adced72376 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/StorageExceptionInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/StorageExceptionInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.09.30
 
-using System;
 using System.Text;
 
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/SyntaxErrorException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/SyntaxErrorException.cs
index 4706a68fcc..95a653ca5f 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/SyntaxErrorException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/SyntaxErrorException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/TransactionSerializationFailureException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/TransactionSerializationFailureException.cs
index ae56fb09d4..2b0a292196 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/TransactionSerializationFailureException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/TransactionSerializationFailureException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/UniqueConstraintViolationException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/UniqueConstraintViolationException.cs
index cb59f90e40..5ba10ed92c 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/UniqueConstraintViolationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/UniqueConstraintViolationException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.08
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Exceptions/VersionConflictException.cs b/Orm/Xtensive.Orm/Orm/Exceptions/VersionConflictException.cs
index 40dca55183..b6b3e5102c 100644
--- a/Orm/Xtensive.Orm/Orm/Exceptions/VersionConflictException.cs
+++ b/Orm/Xtensive.Orm/Orm/Exceptions/VersionConflictException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.17
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/ForeignKeyMode.cs b/Orm/Xtensive.Orm/Orm/ForeignKeyMode.cs
index 98ad4b04e1..6a3b4455b1 100644
--- a/Orm/Xtensive.Orm/Orm/ForeignKeyMode.cs
+++ b/Orm/Xtensive.Orm/Orm/ForeignKeyMode.cs
@@ -4,7 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.12.31
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IGenerationTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IGenerationTerm.cs
index 8385288fed..a0488cd21b 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IGenerationTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IGenerationTerm.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Interfaces
 {
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IOperator.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IOperator.cs
index 8de8348187..49f45bdc6a 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IOperator.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IOperator.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.FullTextSearchCondition.Nodes;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Interfaces
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityOperandsConstructionFlow.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityOperandsConstructionFlow.cs
index 8a554466ea..56ca788940 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityOperandsConstructionFlow.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityOperandsConstructionFlow.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Interfaces
 {
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityTerm.cs
index 5263129c06..3eb59d4c2a 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IProximityTerm.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Interfaces
 {
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTerm.cs
index f221a17ac9..31076f137e 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTerm.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Interfaces
 {
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTermConstructionFlow.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTermConstructionFlow.cs
index 9572c86128..0c22fab7dc 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTermConstructionFlow.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Interfaces/IWeightedTermConstructionFlow.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Interfaces
 {
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Internals/SearchConditionNodeFactory.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Internals/SearchConditionNodeFactory.cs
index 75f6aecbd6..9ae6af334a 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Internals/SearchConditionNodeFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Internals/SearchConditionNodeFactory.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 using Xtensive.Orm.FullTextSearchCondition.Nodes;
 
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/CustomProximityTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/CustomProximityTerm.cs
index 38a8a5549a..9cb4faf1e6 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/CustomProximityTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/CustomProximityTerm.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenerationTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenerationTerm.cs
index ae7f92cdc4..c498d3919f 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenerationTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenerationTerm.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenericProximityTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenericProximityTerm.cs
index b265cb7479..73fad9afc8 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenericProximityTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/GenericProximityTerm.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Nodes
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/Operator.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/Operator.cs
index d88e1caf78..f72f850fc7 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/Operator.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/Operator.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 using Xtensive.Orm.FullTextSearchCondition.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/WeightedTerm.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/WeightedTerm.cs
index 9ce27c13f4..d37f108200 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/WeightedTerm.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/Nodes/WeightedTerm.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 
 namespace Xtensive.Orm.FullTextSearchCondition.Nodes
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/ProximityOperandEndpoint.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/ProximityOperandEndpoint.cs
index e8a23d85c8..e9aeefa031 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/ProximityOperandEndpoint.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/ProximityOperandEndpoint.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 using Xtensive.Orm.FullTextSearchCondition.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/WeightedTermEndpoint.cs b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/WeightedTermEndpoint.cs
index 7db2ffc6e0..679a88b5b0 100644
--- a/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/WeightedTermEndpoint.cs
+++ b/Orm/Xtensive.Orm/Orm/FullTextSearchCondition/WeightedTermEndpoint.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Globalization;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/DbConnectionAccessor.cs b/Orm/Xtensive.Orm/Orm/Interfaces/DbConnectionAccessor.cs
index 9c306daf49..5a64fd5e07 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/DbConnectionAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/DbConnectionAccessor.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/ICompletableScope.cs b/Orm/Xtensive.Orm/Orm/Interfaces/ICompletableScope.cs
index 2a7b5a73b5..bb9d980e08 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/ICompletableScope.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/ICompletableScope.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.04
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IDbConnectionAccessor.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IDbConnectionAccessor.cs
index 6a7231aa87..ea5b689f1f 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IDbConnectionAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IDbConnectionAccessor.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IHasVersionRoots.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IHasVersionRoots.cs
index 9ba7d05d75..72b8a908b7 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IHasVersionRoots.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IHasVersionRoots.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.07
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IModule2.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IModule2.cs
index aa46cd37d4..83c0777988 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IModule2.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IModule2.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.09.27
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Building;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IOperation.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IOperation.cs
index ecde9d720b..e1cbc4fd37 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.21
 
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Orm.Operations;
 
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IOperationLogger.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IOperationLogger.cs
index 37de632121..2982202197 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IOperationLogger.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IOperationLogger.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.21
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IOperationSequence.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IOperationSequence.cs
index b841ef8215..012a8573c9 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IOperationSequence.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IOperationSequence.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.03.01
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IQueryRootBuilder.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IQueryRootBuilder.cs
index d8e93ac60d..262985df68 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IQueryRootBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IQueryRootBuilder.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.23
 
-using System;
 using System.Linq.Expressions;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/ISessionSource.cs b/Orm/Xtensive.Orm/Orm/Interfaces/ISessionSource.cs
index a892dbcbd0..7bec6a7a00 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/ISessionSource.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/ISessionSource.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm;
 using Xtensive.Orm.Configuration;
 
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IUniqueOperation.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IUniqueOperation.cs
index 14ef72ad64..55d893e204 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IUniqueOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IUniqueOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2010.02.18
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/IVersionSetProvider.cs b/Orm/Xtensive.Orm/Orm/Interfaces/IVersionSetProvider.cs
index 6761bbd113..69b772acd5 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/IVersionSetProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/IVersionSetProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.21
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/KeyGenerator.cs b/Orm/Xtensive.Orm/Orm/Interfaces/KeyGenerator.cs
index 096a8e01fb..5366e56b22 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/KeyGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/KeyGenerator.cs
@@ -1,4 +1,4 @@
-// Copyright (C) 2012 Xtensive LLC.
+// Copyright (C) 2012 Xtensive LLC.
 // All rights reserved.
 // For conditions of distribution and use, see license.
 // Created by: Denis Krjuchkov
@@ -6,6 +6,7 @@
 
 using Xtensive.Orm.Model;
 using Xtensive.Tuples;
+using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Interfaces/TemporaryKeyGenerator.cs b/Orm/Xtensive.Orm/Orm/Interfaces/TemporaryKeyGenerator.cs
index b943b73eba..0ca05c9180 100644
--- a/Orm/Xtensive.Orm/Orm/Interfaces/TemporaryKeyGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Interfaces/TemporaryKeyGenerator.cs
@@ -1,4 +1,4 @@
-// Copyright (C) 2012 Xtensive LLC.
+// Copyright (C) 2012 Xtensive LLC.
 // All rights reserved.
 // For conditions of distribution and use, see license.
 // Created by: Denis Krjuchkov
@@ -6,6 +6,7 @@
 
 using Xtensive.Orm.Configuration;
 using Xtensive.Tuples;
+using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Activator.cs b/Orm/Xtensive.Orm/Orm/Internals/Activator.cs
index 36263f1730..f4cdc785d2 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Activator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Activator.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.01
 
-using System;
 using System.Collections.Concurrent;
 using System.Reflection;
 using FieldInfo = Xtensive.Orm.Model.FieldInfo;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntityChangeRegistry.cs b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntityChangeRegistry.cs
index 1816285048..d9f1fe0af9 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntityChangeRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntityChangeRegistry.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.03
 
-using System;
-using System.Collections.Generic;
 
 
 namespace Xtensive.Orm.Internals
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntitySetChangeRegistry.cs b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntitySetChangeRegistry.cs
index 98cc185073..f484c35811 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntitySetChangeRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/EntitySetChangeRegistry.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.03.27
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Internals
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/NonPairedReferenceChangesRegistry.cs b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/NonPairedReferenceChangesRegistry.cs
index 67039d04ff..412685ac49 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/NonPairedReferenceChangesRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/NonPairedReferenceChangesRegistry.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.06.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/ReferenceFieldsChangesRegistry.cs b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/ReferenceFieldsChangesRegistry.cs
index b7c0eef3e3..cd89e38126 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/ReferenceFieldsChangesRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/ReferenceFieldsChangesRegistry.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.04.07
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/RegistryItems{T}.cs b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/RegistryItems{T}.cs
index b8a1e1caf4..8f34b9a717 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/RegistryItems{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ChangeRegistries/RegistryItems{T}.cs
@@ -3,7 +3,6 @@
 // See the License.txt file in the project root for more information.
 
 using System.Collections;
-using System.Collections.Generic;
 
 
 namespace Xtensive.Orm.Internals
diff --git a/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryProcessingScope.cs b/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryProcessingScope.cs
index 684a473415..edeaa10548 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryProcessingScope.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryProcessingScope.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.27
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Linq.Expressions.Visitors;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryRunner.cs b/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryRunner.cs
index 9769704516..2dc7476062 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryRunner.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/CompiledQueryRunner.cs
@@ -4,13 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Caching;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/CompletableScope{T}.cs b/Orm/Xtensive.Orm/Orm/Internals/CompletableScope{T}.cs
index 7ae62743af..430d08724f 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/CompletableScope{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/CompletableScope{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.04
 
-using System;
 
 namespace Xtensive.Orm.Internals
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/EntityDataReader.cs b/Orm/Xtensive.Orm/Orm/Internals/EntityDataReader.cs
index 7c80bda480..10bab20093 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/EntityDataReader.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/EntityDataReader.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.02
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Caching;
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Materialization;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/EntitySetItem.cs b/Orm/Xtensive.Orm/Orm/Internals/EntitySetItem.cs
index 154cbe6390..66f3ca30a0 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/EntitySetItem.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/EntitySetItem.cs
@@ -4,7 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.09.05
 
-using System;
 using Xtensive.Orm.Weaving;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/EntitySetState.cs b/Orm/Xtensive.Orm/Orm/Internals/EntitySetState.cs
index c7b50b73ba..9ad7e3aa12 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/EntitySetState.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/EntitySetState.cs
@@ -4,11 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.14
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
 using Xtensive.Caching;
 using Xtensive.Core;
 using KeyCache = Xtensive.Caching.ICache<Xtensive.Orm.Key, Xtensive.Orm.Key>;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs b/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs
index 29c75b99f9..e072ecaeb1 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.04
 
-using System;
 using Xtensive.Tuples;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor.cs
index d2c7a37d24..7837d07356 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.19
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessorProvider.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessorProvider.cs
index 410ed7a757..0b56c74b86 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessorProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessorProvider.cs
@@ -4,12 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.19
 
-using System;
 using System.Reflection;
 using Xtensive.Collections;
 using Xtensive.Orm.Internals.FieldAccessors;
 using Xtensive.Reflection;
-using System.Linq;
 using FieldInfo=Xtensive.Orm.Model.FieldInfo;
 using TypeInfo = Xtensive.Orm.Model.TypeInfo;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/CachingFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/CachingFieldAccessor.cs
index 91780d5223..856153517b 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/CachingFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/CachingFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.07.08
 
-using System;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Internals.FieldAccessors
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/DefaultFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/DefaultFieldAccessor.cs
index 68bcf69823..2002174bd9 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/DefaultFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/DefaultFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.05.26
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Orm.Internals.FieldAccessors
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntityFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntityFieldAccessor.cs
index 5a4cc40d41..22e47f05fa 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntityFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntityFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.05.26
 
-using System;
 
 using Xtensive.Tuples;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntitySetFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntitySetFieldAccessor.cs
index a4d63046ba..35ba9dfd72 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntitySetFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EntitySetFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.09.05
 
-using System;
 
 namespace Xtensive.Orm.Internals.FieldAccessors
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EnumFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EnumFieldAccessor.cs
index 35580919a3..60e6405ed5 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EnumFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/EnumFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.06.07
 
-using System;
 using Xtensive.Reflection;
 using Xtensive.Tuples;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/KeyFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/KeyFieldAccessor.cs
index fc877cb768..7f0b936610 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/KeyFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/KeyFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.11.21
 
-using System;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/StructureFieldAccessor.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/StructureFieldAccessor.cs
index 0936daf0bb..f24841d9fd 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/StructureFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessors/StructureFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.05.30
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor{T}.cs b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor{T}.cs
index 4c83a9b523..e7f8699f01 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/FieldAccessor{T}.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.06.02
 
-using System;
 using Xtensive.Orm.Model;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/GenericKeyFactory.cs b/Orm/Xtensive.Orm/Orm/Internals/GenericKeyFactory.cs
index 0f4fccbe22..ef944a4d7a 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/GenericKeyFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/GenericKeyFactory.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.27
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Model;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyFactory.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyFactory.cs
index 32a8eda870..28340c0630 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyFactory.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGeneratorRegistry.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGeneratorRegistry.cs
index e6e4b39d26..735e4cbfbd 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGeneratorRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGeneratorRegistry.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.08
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/CachingSequence.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/CachingSequence.cs
index 7654d23751..c8fd2ef8f7 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/CachingSequence.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/CachingSequence.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.17
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/SessionCachingSequenceProvider.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/SessionCachingSequenceProvider.cs
index eacc00c93c..580004d10b 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/SessionCachingSequenceProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/Caching/SessionCachingSequenceProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.17
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GloballyUniqueValueGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GloballyUniqueValueGenerator.cs
index 7a0f2ec2bd..e595d662d7 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GloballyUniqueValueGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GloballyUniqueValueGenerator.cs
@@ -1,4 +1,4 @@
-// Copyright (C) 2012 Xtensive LLC.
+// Copyright (C) 2012 Xtensive LLC.
 // All rights reserved.
 // For conditions of distribution and use, see license.
 // Created by: Denis Krjuchkov
@@ -6,6 +6,7 @@
 
 using Xtensive.Orm.Model;
 using Xtensive.Tuples;
+using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm.Internals.KeyGenerators
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GuidGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GuidGenerator.cs
index 237f6853c5..81e27ac5aa 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GuidGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/GuidGenerator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.08
 
-using System;
 
 namespace Xtensive.Orm.Internals.KeyGenerators
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/StringGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/StringGenerator.cs
index 72aea3db50..3f659f297e 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/StringGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/StringGenerator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.08
 
-using System;
 
 namespace Xtensive.Orm.Internals.KeyGenerators
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/TemporarySequentalGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/TemporarySequentalGenerator.cs
index feff88ed67..ac5810ef5a 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/TemporarySequentalGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyGenerators/TemporarySequentalGenerator.cs
@@ -1,4 +1,4 @@
-// Copyright (C) 2012 Xtensive LLC.
+// Copyright (C) 2012 Xtensive LLC.
 // All rights reserved.
 // For conditions of distribution and use, see license.
 // Created by: Denis Krjuchkov
@@ -8,6 +8,7 @@
 using Xtensive.Comparison;
 using Xtensive.Orm.Model;
 using Xtensive.Tuples;
+using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm.Internals.KeyGenerators
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/KeyRemapper.cs b/Orm/Xtensive.Orm/Orm/Internals/KeyRemapper.cs
index 615f42d08a..67d65f53ac 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/KeyRemapper.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/KeyRemapper.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.05.06
 
-using System;
-using System.Linq;
 using Xtensive.Tuples.Transform;
 
 namespace Xtensive.Orm.Internals
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3,T4}.cs b/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3,T4}.cs
index 4825bed798..a49ff297fa 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3,T4}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3,T4}.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.13
 
-using System;
-using System.Collections.Generic;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3}.cs b/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3}.cs
index f1c9fa0a8e..9b8f5d9603 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2,T3}.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.13
 
-using System;
-using System.Collections.Generic;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2}.cs b/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2}.cs
index 9f4834c3e5..0b8244c440 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Key{T1,T2}.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.13
 
-using System;
-using System.Collections.Generic;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Key{T}.cs b/Orm/Xtensive.Orm/Orm/Internals/Key{T}.cs
index 332f886dcf..ac288ee16f 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Key{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Key{T}.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.13
 
-using System;
-using System.Collections.Generic;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/LongKey.cs b/Orm/Xtensive.Orm/Orm/Internals/LongKey.cs
index 2203651e57..612171ee8c 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/LongKey.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/LongKey.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.10.20
 
-using System;
 using Xtensive.Orm.Model;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncAction.cs b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncAction.cs
index 4dae8aeeb2..3753404743 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncAction.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncAction.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.07.15
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.ReferentialIntegrity;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncActionSet.cs b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncActionSet.cs
index 12135de4ed..a2d5ef0773 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncActionSet.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncActionSet.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.10
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.ReferentialIntegrity;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncContext.cs b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncContext.cs
index 01eff33a9e..4097184e44 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncContext.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.08
 
-using System;
-using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncManager.cs b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncManager.cs
index 9b72b3612a..c11fc0044d 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncManager.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/PairIntegrity/SyncManager.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.10.08
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/PersistAction.cs b/Orm/Xtensive.Orm/Orm/Internals/PersistAction.cs
index 9364214d55..f09255049c 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/PersistAction.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/PersistAction.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.09
 
-using System;
 using Xtensive.Orm.Providers;
 
 namespace Xtensive.Orm.Internals
diff --git a/Orm/Xtensive.Orm/Orm/Internals/PersistActionGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/PersistActionGenerator.cs
index 6e57f6f784..205d29e384 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/PersistActionGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/PersistActionGenerator.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.22
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Providers;
 
 namespace Xtensive.Orm.Internals
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Pinner.cs b/Orm/Xtensive.Orm/Orm/Internals/Pinner.cs
index fc73f3f9fb..5126a50855 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Pinner.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Pinner.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.11
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityContainer.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityContainer.cs
index 81e2deac96..347ebdb541 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityContainer.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityContainer.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityGroupTask.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityGroupTask.cs
index a500c4abde..1b3f7f19cb 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityGroupTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityGroupTask.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Rse;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs
index b166b1af98..99c795ab5d 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.09
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Fetcher.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Fetcher.cs
index 9cbfff4730..0abcf8b025 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Fetcher.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Fetcher.cs
@@ -4,10 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.20
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/GraphContainer.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/GraphContainer.cs
index ed4300d2f8..0d014ca496 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/GraphContainer.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/GraphContainer.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.17
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Tuples;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMap.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMap.cs
index 50d7ed2c89..f413ed37a6 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMap.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMap.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.24
 
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMapBuilder.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMapBuilder.cs
index 0d6c2bd7d8..92f87a25e8 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMapBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ExpressionMapBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/IHasNestedNodes.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/IHasNestedNodes.cs
index 50d1354035..1477093b0d 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/IHasNestedNodes.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/IHasNestedNodes.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.01.14
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Orm.Internals.Prefetch
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/KeyExtractorNode.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/KeyExtractorNode.cs
index 9b3af6a0e6..f758f83b31 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/KeyExtractorNode.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/KeyExtractorNode.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.01.13
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/Node.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/Node.cs
index 7031d71735..0871ac1113 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/Node.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/Node.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.01.13
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeAggregator.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeAggregator.cs
index d239cce2a7..f2703e866b 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeAggregator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeAggregator.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2011.01.13
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 
 namespace Xtensive.Orm.Internals.Prefetch
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeBuilder.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeBuilder.cs
index ebc5ad3fad..25d29aded6 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/NodeBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ReferenceNode.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ReferenceNode.cs
index 5bceb8dc84..f0b4826b62 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ReferenceNode.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/ReferenceNode.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.11.19
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/SetNode.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/SetNode.cs
index 5650ef97a9..5645c85e68 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/SetNode.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/Nodes/SetNode.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.11.19
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchFieldDescriptor.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchFieldDescriptor.cs
index 9d9b413977..9c8e21b731 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchFieldDescriptor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchFieldDescriptor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.23
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs
index 4bc650e672..19fab1c51d 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Internals.Prefetch
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchKeyIterator.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchKeyIterator.cs
index 0b5b0029a6..86f8ee42ec 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchKeyIterator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchKeyIterator.cs
@@ -5,8 +5,6 @@
 // Created:    2011.01.11
 
 using System.Collections;
-using System.Collections.Generic;
-using System.Threading;
 
 namespace Xtensive.Orm.Internals.Prefetch
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs
index d8ac2ebf44..fb16f5235f 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs
@@ -4,11 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.03
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Caching;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchProcessor.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchProcessor.cs
index 96e240497c..89ce5428e2 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchProcessor.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2010.11.22
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Internals.Prefetch
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryAsyncEnumerable.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryAsyncEnumerable.cs
index cd553decef..b26249fb4c 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryAsyncEnumerable.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryAsyncEnumerable.cs
@@ -2,11 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryEnumerable.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryEnumerable.cs
index 012bb5170f..ad874f11d2 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryEnumerable.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchQueryEnumerable.cs
@@ -3,10 +3,7 @@
 // See the License.txt file in the project root for more information.
 // Created by: Alexis Kochetov
 // Created:    2010.11.18
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/ReferencedEntityContainer.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/ReferencedEntityContainer.cs
index b5f6305c02..0fcaa35d5c 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/ReferencedEntityContainer.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/ReferencedEntityContainer.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/RootEntityContainer.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/RootEntityContainer.cs
index dc0a1f7a41..e0a824b494 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/RootEntityContainer.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/RootEntityContainer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.03
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/StrongReferenceContainer.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/StrongReferenceContainer.cs
index eb01503ba4..3c321c0db2 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/StrongReferenceContainer.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/StrongReferenceContainer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.10.08
 
-using System;
 
 
 namespace Xtensive.Orm.Internals.Prefetch
diff --git a/Orm/Xtensive.Orm/Orm/Internals/QueryTask.cs b/Orm/Xtensive.Orm/Orm/Internals/QueryTask.cs
index 3a9517948c..7012c603f1 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/QueryTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/QueryTask.cs
@@ -4,9 +4,7 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.19
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ReferentialActions.cs b/Orm/Xtensive.Orm/Orm/Internals/ReferentialActions.cs
index 6f935d8bec..253e28d741 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ReferentialActions.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ReferentialActions.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.07.15
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.PairIntegrity;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/ClearActionProcessor.cs b/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/ClearActionProcessor.cs
index a3011d5fab..4fcd4449e5 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/ClearActionProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/ClearActionProcessor.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.01
 
-using System;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalContext.cs b/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalContext.cs
index f44162d7bc..2c239e5676 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalContext.cs
@@ -4,11 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.02
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
-using System.Linq;
 
 namespace Xtensive.Orm.ReferentialIntegrity
 {
diff --git a/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalProcessor.cs b/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalProcessor.cs
index d91a50e110..969dbb2b0f 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/ReferentialIntegrity/RemovalProcessor.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/RemapContext.cs b/Orm/Xtensive.Orm/Orm/Internals/RemapContext.cs
index 74c6d882d6..a28f5c0eac 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/RemapContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/RemapContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2014.04.07
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/SortingPersistActionGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/SortingPersistActionGenerator.cs
index 5478d81ca3..ed296688fe 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/SortingPersistActionGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/SortingPersistActionGenerator.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections.Graphs;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/StorageNodeRegistry.cs b/Orm/Xtensive.Orm/Orm/Internals/StorageNodeRegistry.cs
index 8e42e07840..0fe69334d4 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/StorageNodeRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/StorageNodeRegistry.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Internals
diff --git a/Orm/Xtensive.Orm/Orm/Internals/TupleExtensions.cs b/Orm/Xtensive.Orm/Orm/Internals/TupleExtensions.cs
index 9c824c6189..6e8ed2f0f4 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/TupleExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/TupleExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.29
 
-using System;
 using Xtensive.Core;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Internals/TypeMapping.cs b/Orm/Xtensive.Orm/Orm/Internals/TypeMapping.cs
index 9848fbaec1..04233194fa 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/TypeMapping.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/TypeMapping.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.08
 
-using System.Collections.Generic;
 using Xtensive.Tuples.Transform;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/VersionGenerator.cs b/Orm/Xtensive.Orm/Orm/Internals/VersionGenerator.cs
index 5093c8aa7b..843d4401a2 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/VersionGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/VersionGenerator.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.06
 
-using System;
 using Xtensive.Core;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Internals/WellKnownOrmTypes.cs b/Orm/Xtensive.Orm/Orm/Internals/WellKnownOrmTypes.cs
index 9339d2e43c..f33d2eeab7 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/WellKnownOrmTypes.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/WellKnownOrmTypes.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Linq.Expressions;
diff --git a/Orm/Xtensive.Orm/Orm/Key.cs b/Orm/Xtensive.Orm/Orm/Key.cs
index 893febf90f..8e445a1ab8 100644
--- a/Orm/Xtensive.Orm/Orm/Key.cs
+++ b/Orm/Xtensive.Orm/Orm/Key.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2007.12.20
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/KeyEventArgs.cs b/Orm/Xtensive.Orm/Orm/KeyEventArgs.cs
index 4f4db93a88..0b47280e13 100644
--- a/Orm/Xtensive.Orm/Orm/KeyEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/KeyEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.19
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/KeyMapping.cs b/Orm/Xtensive.Orm/Orm/KeyMapping.cs
index 68178f2c35..cc33b6cd19 100644
--- a/Orm/Xtensive.Orm/Orm/KeyMapping.cs
+++ b/Orm/Xtensive.Orm/Orm/KeyMapping.cs
@@ -4,10 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.19
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ColumnExtractionModes.cs b/Orm/Xtensive.Orm/Orm/Linq/ColumnExtractionModes.cs
index 840d5aeec1..62fecc9c80 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ColumnExtractionModes.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ColumnExtractionModes.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.27
 
-using System;
 
 namespace Xtensive.Orm.Linq
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ExpressionEvaluator.cs b/Orm/Xtensive.Orm/Orm/Linq/ExpressionEvaluator.cs
index 51ce8c6bb0..da0f69c463 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ExpressionEvaluator.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ExpressionEvaluator.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.12.18
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ExpressionExtensions.cs b/Orm/Xtensive.Orm/Orm/Linq/ExpressionExtensions.cs
index f6273e3e30..e1495ba7bc 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ExpressionExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ExpressionExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.12.02
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ColumnExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ColumnExpression.cs
index 6f997f3559..703b6424e6 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ColumnExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ColumnExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ConstructorExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ConstructorExpression.cs
index 3b199e6ae1..c45c816b3e 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ConstructorExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ConstructorExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.16
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using System.Reflection;
@@ -13,7 +11,6 @@
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Expressions;
 using Xtensive.Orm.Linq.Expressions.Visitors;
-using System.Linq;
 
 namespace Xtensive.Orm.Linq
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityExpression.cs
index 575b18d804..2a8fade064 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityExpression.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.05
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityFieldExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityFieldExpression.cs
index a6240b64ed..f231de87bf 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityFieldExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntityFieldExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntitySetExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntitySetExpression.cs
index 458ca11bd6..9d2683b9ea 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntitySetExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/EntitySetExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.05
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpression.cs
index 79d9755d5b..0c1dc6df52 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
 using System.Linq.Expressions;
 
 namespace Xtensive.Orm.Linq.Expressions
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpressionType.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpressionType.cs
index fff8f2aad6..481cb0906c 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpressionType.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ExtendedExpressionType.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.05
 
-using System;
 
 namespace Xtensive.Orm.Linq.Expressions
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/FieldExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/FieldExpression.cs
index b5aee9f1d4..be5a61c5c1 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/FieldExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/FieldExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.05
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using FieldInfo = Xtensive.Orm.Model.FieldInfo;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/FullTextExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/FullTextExpression.cs
index 2e5477fcd1..6df03c4766 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/FullTextExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/FullTextExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.28
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/GroupingExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/GroupingExpression.cs
index 5f9663e10f..9895b7c2d1 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/GroupingExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/GroupingExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.05.19
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Orm.Linq.Expressions.Visitors;
 using Xtensive.Orm.Rse;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IEntityExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IEntityExpression.cs
index bf295bce14..baf9456961 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IEntityExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IEntityExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.14
 
-using System;
 namespace Xtensive.Orm.Linq.Expressions
 {
   internal interface IEntityExpression : IPersistentExpression
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IMappedExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IMappedExpression.cs
index 2bd7e557ff..d77efc0abe 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IMappedExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IMappedExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IPersistentExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IPersistentExpression.cs
index 3de123dbc4..89fb349dd1 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IPersistentExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Interfaces/IPersistentExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System.Collections.Generic;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Linq.Expressions
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ItemProjectorExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ItemProjectorExpression.cs
index bdd721afb6..3cf61632ca 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ItemProjectorExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ItemProjectorExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Expressions.Visitors;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/KeyExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/KeyExpression.cs
index 0d8b6ff217..1688f536e8 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/KeyExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/KeyExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.05
 
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/LocalCollectionExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/LocalCollectionExpression.cs
index 2e2eef5584..ac5a6e18a5 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/LocalCollectionExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/LocalCollectionExpression.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.09.09
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/MarkerType.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/MarkerType.cs
index 4e8267b51a..bac020768c 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/MarkerType.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/MarkerType.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.06.23
 
-using System;
 
 namespace Xtensive.Orm.Linq.Expressions
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ParameterizedExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ParameterizedExpression.cs
index d5f627fcb2..b5b91c9099 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ParameterizedExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ParameterizedExpression.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.18
 
-using System;
 using System.Linq.Expressions;
 
 namespace Xtensive.Orm.Linq.Expressions
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/PersistentFieldExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/PersistentFieldExpression.cs
index c718771c1e..375fd0a5a1 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/PersistentFieldExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/PersistentFieldExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ProjectionExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ProjectionExpression.cs
index aa76d8f37b..bdf8c1874d 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ProjectionExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ProjectionExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.12.11
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ResultAccessMethod.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ResultAccessMethod.cs
index 6d910f7bfa..f6b1faa3ad 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/ResultAccessMethod.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/ResultAccessMethod.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.24
 
-using System;
 
 namespace Xtensive.Orm.Linq.Expressions
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureExpression.cs
index bb31cd358d..bfde2b17cd 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureExpression.cs
@@ -4,12 +4,9 @@
 // Created by: Alexey Gamzov
 // Created:    2009.09.29
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Linq.Expressions
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureFieldExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureFieldExpression.cs
index f08de19cdf..f5dba51778 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureFieldExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/StructureFieldExpression.cs
@@ -4,12 +4,9 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.05
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
-using System.Linq;
 
 namespace Xtensive.Orm.Linq.Expressions
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/SubQueryExpression.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/SubQueryExpression.cs
index f34c0312e7..4a50b40b01 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/SubQueryExpression.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/SubQueryExpression.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.05.19
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Expressions.Visitors;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ApplyParameterAccessVisitor.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ApplyParameterAccessVisitor.cs
index 74032f0e59..9c23b9f359 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ApplyParameterAccessVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ApplyParameterAccessVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.06.02
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Orm.Rse;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ColumnGatherer.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ColumnGatherer.cs
index 4516c5a72b..62ad42e139 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ColumnGatherer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ColumnGatherer.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EntityExpressionJoiner.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EntityExpressionJoiner.cs
index 756b347572..39a9396a8e 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EntityExpressionJoiner.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EntityExpressionJoiner.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.02
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Linq.Expressions.Visitors
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EnumRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EnumRewriter.cs
index 84d5700c61..7c7422cad0 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EnumRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/EnumRewriter.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Reflection;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionReplacer.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionReplacer.cs
index dfbb2b6a5c..5b51c67195 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionReplacer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionReplacer.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.27
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionVisitor.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionVisitor.cs
index 582b33eb7b..83080c16a6 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.06
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Linq;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/GenericExpressionVisitor.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/GenericExpressionVisitor.cs
index c017cf8011..623d65ae5b 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/GenericExpressionVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/GenericExpressionVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.21
 
-using System;
 using System.Linq.Expressions;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/IncludeFilterMappingGatherer.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/IncludeFilterMappingGatherer.cs
index 7aead4010a..84705b9a06 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/IncludeFilterMappingGatherer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/IncludeFilterMappingGatherer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.11.16
 
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/OwnerRemover.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/OwnerRemover.cs
index 6ec15951ca..b4379253a4 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/OwnerRemover.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/OwnerRemover.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.26
 
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/PersistentExpressionVisitor.cs b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/PersistentExpressionVisitor.cs
index cba7381f44..a75a4fa746 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/PersistentExpressionVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/PersistentExpressionVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.07
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/FieldExtractor.cs b/Orm/Xtensive.Orm/Orm/Linq/FieldExtractor.cs
index 1a918ac986..9f21ebf909 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/FieldExtractor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/FieldExtractor.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.14
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Grouping.cs b/Orm/Xtensive.Orm/Orm/Linq/Grouping.cs
index dbdd873c01..04f87389c0 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Grouping.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Grouping.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.17
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Expressions;
 using Xtensive.Orm.Linq.Materialization;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter.cs b/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter.cs
index dce583958f..a276422bf6 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.01
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter{TItem}.cs b/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter{TItem}.cs
index 9e8cc11887..a58e16c660 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter{TItem}.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ItemToTupleConverter{TItem}.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.01
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/LinqBindingCollection.cs b/Orm/Xtensive.Orm/Orm/Linq/LinqBindingCollection.cs
index 17baecb416..4ec63082cd 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/LinqBindingCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/LinqBindingCollection.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.06.30
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Orm.Linq.Expressions;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/LocalCollectionKeyTypeExtractor.cs b/Orm/Xtensive.Orm/Orm/Linq/LocalCollectionKeyTypeExtractor.cs
index db5884c8d2..e560e73027 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/LocalCollectionKeyTypeExtractor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/LocalCollectionKeyTypeExtractor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.12.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Materialization/ExpressionMaterializer.cs b/Orm/Xtensive.Orm/Orm/Linq/Materialization/ExpressionMaterializer.cs
index a501a3c2e4..3a3d501285 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Materialization/ExpressionMaterializer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Materialization/ExpressionMaterializer.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.05.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Materialization/ItemMaterializer.cs b/Orm/Xtensive.Orm/Orm/Linq/Materialization/ItemMaterializer.cs
index 343b60b6d4..1bd264d666 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Materialization/ItemMaterializer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Materialization/ItemMaterializer.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Rse;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationContext.cs b/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationContext.cs
index 0909a1c341..c180b48a5e 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationContext.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.29
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Tuples.Transform;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationHelper.cs b/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationHelper.cs
index 025523cf85..ad5a8d56ca 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationHelper.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializationHelper.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Materialization/Materializer.cs b/Orm/Xtensive.Orm/Orm/Linq/Materialization/Materializer.cs
index 92787f0752..01bdc1a919 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Materialization/Materializer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Materialization/Materializer.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Rse;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializingReader.cs b/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializingReader.cs
index f1e600fe4b..7d3ddf821c 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializingReader.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Materialization/MaterializingReader.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Rse;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider.cs b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider.cs
index 0beceb65b5..782c564d93 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.03.27
 
-using System;
 using System.Reflection;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider{T}.cs b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider{T}.cs
index fe4976d1f0..381d47d5cc 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider{T}.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/Interfaces/IMemberCompilerProvider{T}.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.09
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 
 namespace Xtensive.Orm.Linq.MemberCompilation
diff --git a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider-CreateCompiler.cs b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider-CreateCompiler.cs
index 9f6b5cbc1f..b17dcc4e43 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider-CreateCompiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider-CreateCompiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.03.10
 
-using System;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider.cs b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider.cs
index 4a643c3f11..9c05628783 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProvider.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.09
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProviderFactory.cs b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProviderFactory.cs
index 6e646fc6f9..9036f5be0e 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProviderFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/MemberCompilation/MemberCompilerProviderFactory.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtia
 // Created:    2009.03.27
 
-using System;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Activator = System.Activator;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/MemberType.cs b/Orm/Xtensive.Orm/Orm/Linq/MemberType.cs
index 155d113cb2..a2cfc85e74 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/MemberType.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/MemberType.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.01.26
 
-using System;
 
 namespace Xtensive.Orm.Linq
 {
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Model/QueryParser.cs b/Orm/Xtensive.Orm/Orm/Linq/Model/QueryParser.cs
index e92b50f3b0..69dbf23934 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Model/QueryParser.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Model/QueryParser.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.11
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Model/QueryableMethodInfo.cs b/Orm/Xtensive.Orm/Orm/Linq/Model/QueryableMethodInfo.cs
index 929bd33247..246adb0ac7 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Model/QueryableMethodInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Model/QueryableMethodInfo.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ParameterAccessorFactory.cs b/Orm/Xtensive.Orm/Orm/Linq/ParameterAccessorFactory.cs
index 72b56bff07..ddc4223ded 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ParameterAccessorFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ParameterAccessorFactory.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/ParameterizedQuery.cs b/Orm/Xtensive.Orm/Orm/Linq/ParameterizedQuery.cs
index 202d2b3332..aa80e0a97d 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/ParameterizedQuery.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/ParameterizedQuery.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.27
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Linq
diff --git a/Orm/Xtensive.Orm/Orm/Linq/QueryHelper.cs b/Orm/Xtensive.Orm/Orm/Linq/QueryHelper.cs
index 6570c42bd5..3feb344469 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/QueryHelper.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/QueryHelper.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.02
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/QueryPreprocessor.cs b/Orm/Xtensive.Orm/Orm/Linq/QueryPreprocessor.cs
index e522e41165..37f8815533 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/QueryPreprocessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/QueryPreprocessor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.08.20
 
-using System;
 using System.Linq.Expressions;
 
 namespace Xtensive.Orm.Linq
diff --git a/Orm/Xtensive.Orm/Orm/Linq/QueryProvider.cs b/Orm/Xtensive.Orm/Orm/Linq/QueryProvider.cs
index 283875c038..4da545b20d 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/QueryProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/QueryProvider.cs
@@ -4,13 +4,9 @@
 // Created by: Alexey Kochetov
 // Created:    2008.11.26
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.ExceptionServices;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Queryable.cs b/Orm/Xtensive.Orm/Orm/Linq/Queryable.cs
index 42affc9d54..aab944bbba 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Queryable.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Queryable.cs
@@ -4,13 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2009.07.01
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Linq
diff --git a/Orm/Xtensive.Orm/Orm/Linq/RemapContext.cs b/Orm/Xtensive.Orm/Orm/Linq/RemapContext.cs
index 8845b632c7..8a4db40ac5 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/RemapContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/RemapContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.06.03
 
-using System;
 using System.Diagnostics;
 using System.Linq.Expressions;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/RemapScope.cs b/Orm/Xtensive.Orm/Orm/Linq/RemapScope.cs
index 0bdbdf50bd..0a3fbe98bb 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/RemapScope.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/RemapScope.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.06.03
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/AggregateOptimizer.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/AggregateOptimizer.cs
index e522903a20..bb95f5525e 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/AggregateOptimizer.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/AggregateOptimizer.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ClosureAccessRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ClosureAccessRewriter.cs
index eb78edb2ef..abcf7d276d 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ClosureAccessRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ClosureAccessRewriter.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.09
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EntitySetAccessRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EntitySetAccessRewriter.cs
index d038287791..614bd2a2cb 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EntitySetAccessRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EntitySetAccessRewriter.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.02
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EqualityRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EqualityRewriter.cs
index 99d59d3a8b..78f3f3c0eb 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EqualityRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/EqualityRewriter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.18
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Reflection;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ParameterRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ParameterRewriter.cs
index d243579e91..2ec5cbe107 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ParameterRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/ParameterRewriter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.04.07
 
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/PersistentIndexerRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/PersistentIndexerRewriter.cs
index 3b7848dcbc..4a4209f044 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/PersistentIndexerRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/PersistentIndexerRewriter.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.22
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SelectManySelectorRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SelectManySelectorRewriter.cs
index d085f4c614..b89bc4b28d 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SelectManySelectorRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SelectManySelectorRewriter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.07.03
 
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Linq;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryDefaultResultRewriter.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryDefaultResultRewriter.cs
index 9b9d394dfa..cbdbd5c9e1 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryDefaultResultRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryDefaultResultRewriter.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryFilterRemover.cs b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryFilterRemover.cs
index 53fdc4eb46..8e20c59b85 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryFilterRemover.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Rewriters/SubqueryFilterRemover.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.04.27
 
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Orm.Rse;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/SortExpressionExtractor.cs b/Orm/Xtensive.Orm/Orm/Linq/SortExpressionExtractor.cs
index c8801d5942..3889fe0dc6 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/SortExpressionExtractor.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/SortExpressionExtractor.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.04.29
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/SubQuery.cs b/Orm/Xtensive.Orm/Orm/Linq/SubQuery.cs
index 32da8bd58c..fa02d61aa9 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/SubQuery.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/SubQuery.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.04.23
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/TranslatedQuery.cs b/Orm/Xtensive.Orm/Orm/Linq/TranslatedQuery.cs
index ff2b72524c..ab09d124b7 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/TranslatedQuery.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/TranslatedQuery.cs
@@ -4,11 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Linq.Expressions;
 using Xtensive.Orm.Linq.Materialization;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Translator.Expressions.cs b/Orm/Xtensive.Orm/Orm/Linq/Translator.Expressions.cs
index 313edef7f7..8047990267 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Translator.Expressions.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Translator.Expressions.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Translator.Materialization.cs b/Orm/Xtensive.Orm/Orm/Linq/Translator.Materialization.cs
index b01b6e43ed..f4af839fa6 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Translator.Materialization.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Translator.Materialization.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.05.28
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs b/Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs
index 6c7583db83..a714abc7c5 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/TranslatorContext.cs b/Orm/Xtensive.Orm/Orm/Linq/TranslatorContext.cs
index 85f70dedf4..551fada07a 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/TranslatorContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/TranslatorContext.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/TranslatorState.cs b/Orm/Xtensive.Orm/Orm/Linq/TranslatorState.cs
index d1a606a69e..2fc64513a3 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/TranslatorState.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/TranslatorState.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.21
 
-using System;
 using System.Linq.Expressions;
 using System.Runtime.CompilerServices;
 
diff --git a/Orm/Xtensive.Orm/Orm/Linq/WellKnownMembers.cs b/Orm/Xtensive.Orm/Orm/Linq/WellKnownMembers.cs
index 44d80ecabf..9d17524586 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/WellKnownMembers.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/WellKnownMembers.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.03.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Linq/WellknownMembers.Queryable.cs b/Orm/Xtensive.Orm/Orm/Linq/WellknownMembers.Queryable.cs
index 1c91d3c038..ee5eb16942 100644
--- a/Orm/Xtensive.Orm/Orm/Linq/WellknownMembers.Queryable.cs
+++ b/Orm/Xtensive.Orm/Orm/Linq/WellknownMembers.Queryable.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Reflection;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Logging/BaseLog.cs b/Orm/Xtensive.Orm/Orm/Logging/BaseLog.cs
index 523c36c201..12792a21bc 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/BaseLog.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/BaseLog.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.10.11
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Logging
diff --git a/Orm/Xtensive.Orm/Orm/Logging/IndentManager.cs b/Orm/Xtensive.Orm/Orm/Logging/IndentManager.cs
index 03cecc7146..a393e7f846 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/IndentManager.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/IndentManager.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.11.11
 
-using System;
-using System.Threading;
 
 namespace Xtensive.Orm.Logging
 {
diff --git a/Orm/Xtensive.Orm/Orm/Logging/Internals/ConsoleWriter.cs b/Orm/Xtensive.Orm/Orm/Logging/Internals/ConsoleWriter.cs
index 6704903878..a464cf238d 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/Internals/ConsoleWriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/Internals/ConsoleWriter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.27
 
-using System;
 
 namespace Xtensive.Orm.Logging
 {
diff --git a/Orm/Xtensive.Orm/Orm/Logging/Internals/DebugOnlyConsoleWriter.cs b/Orm/Xtensive.Orm/Orm/Logging/Internals/DebugOnlyConsoleWriter.cs
index da9c6d7a53..e600cb5242 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/Internals/DebugOnlyConsoleWriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/Internals/DebugOnlyConsoleWriter.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.27
 
-using System;
 using System.Diagnostics;
-using System.Threading;
 
 namespace Xtensive.Orm.Logging
 {
diff --git a/Orm/Xtensive.Orm/Orm/Logging/Internals/InternalLogProvider.cs b/Orm/Xtensive.Orm/Orm/Logging/Internals/InternalLogProvider.cs
index e16f1e5410..e952813e6d 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/Internals/InternalLogProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/Internals/InternalLogProvider.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.27
 
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Logging
diff --git a/Orm/Xtensive.Orm/Orm/Logging/Internals/NullLog.cs b/Orm/Xtensive.Orm/Orm/Logging/Internals/NullLog.cs
index 66b3fdaeb9..2a94d1179e 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/Internals/NullLog.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/Internals/NullLog.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.27
 
-using System;
 
 namespace Xtensive.Orm.Logging
 {
diff --git a/Orm/Xtensive.Orm/Orm/Logging/Internals/SystemClock.cs b/Orm/Xtensive.Orm/Orm/Logging/Internals/SystemClock.cs
index bb2d30215b..56c3313147 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/Internals/SystemClock.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/Internals/SystemClock.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.20
 
-using System;
 
 namespace Xtensive.Orm.Logging
 {
diff --git a/Orm/Xtensive.Orm/Orm/Logging/LogEventInfo.cs b/Orm/Xtensive.Orm/Orm/Logging/LogEventInfo.cs
index e8346e9cfd..31376ded28 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/LogEventInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/LogEventInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.27
 
-using System;
 using System.Globalization;
 using System.Text;
 
diff --git a/Orm/Xtensive.Orm/Orm/Logging/LogManager.cs b/Orm/Xtensive.Orm/Orm/Logging/LogManager.cs
index a87682153d..544cf0245c 100644
--- a/Orm/Xtensive.Orm/Orm/Logging/LogManager.cs
+++ b/Orm/Xtensive.Orm/Orm/Logging/LogManager.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.20
 
-using System;
 using System.Configuration;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Metadata/Assembly.cs b/Orm/Xtensive.Orm/Orm/Metadata/Assembly.cs
index da4c0ef275..b0c49d4ff7 100644
--- a/Orm/Xtensive.Orm/Orm/Metadata/Assembly.cs
+++ b/Orm/Xtensive.Orm/Orm/Metadata/Assembly.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.12.24
 
-using System;
 
 
 namespace Xtensive.Orm.Metadata
diff --git a/Orm/Xtensive.Orm/Orm/Metadata/Extension.cs b/Orm/Xtensive.Orm/Orm/Metadata/Extension.cs
index 6e0179bd37..c3db6447f5 100644
--- a/Orm/Xtensive.Orm/Orm/Metadata/Extension.cs
+++ b/Orm/Xtensive.Orm/Orm/Metadata/Extension.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.12.24
 
-using System;
 
 namespace Xtensive.Orm.Metadata
 {
diff --git a/Orm/Xtensive.Orm/Orm/Metadata/MetadataBase.cs b/Orm/Xtensive.Orm/Orm/Metadata/MetadataBase.cs
index d006f21e4d..f9fad8a4e0 100644
--- a/Orm/Xtensive.Orm/Orm/Metadata/MetadataBase.cs
+++ b/Orm/Xtensive.Orm/Orm/Metadata/MetadataBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.05.14
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Metadata/Type.cs b/Orm/Xtensive.Orm/Orm/Metadata/Type.cs
index a84845dc38..a71c402763 100644
--- a/Orm/Xtensive.Orm/Orm/Metadata/Type.cs
+++ b/Orm/Xtensive.Orm/Orm/Metadata/Type.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.12.24
 
-using System;
 
 
 namespace Xtensive.Orm.Metadata
diff --git a/Orm/Xtensive.Orm/Orm/Model/AssociationInfo.cs b/Orm/Xtensive.Orm/Orm/Model/AssociationInfo.cs
index e30f4cc7e5..42b2dc0b60 100644
--- a/Orm/Xtensive.Orm/Orm/Model/AssociationInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/AssociationInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.02
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Tuples.Transform;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Model/AssociationInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/AssociationInfoCollection.cs
index f8027b4e40..f12af4bc3f 100644
--- a/Orm/Xtensive.Orm/Orm/Model/AssociationInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/AssociationInfoCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.07.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/ColumnAttributes.cs b/Orm/Xtensive.Orm/Orm/Model/ColumnAttributes.cs
index 8e84b1fc09..d9244bc55e 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ColumnAttributes.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ColumnAttributes.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.10.03
 
-using System;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/ColumnGroup.cs b/Orm/Xtensive.Orm/Orm/Model/ColumnGroup.cs
index c77ba3312c..3ec74c3e8e 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ColumnGroup.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ColumnGroup.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.08.01
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/ColumnIndexMap.cs b/Orm/Xtensive.Orm/Orm/Model/ColumnIndexMap.cs
index 9e49ed67c6..790ea6c6b3 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ColumnIndexMap.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ColumnIndexMap.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.04
 
-using System;
-using System.Collections.Generic;
 
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/ColumnInfo.cs b/Orm/Xtensive.Orm/Orm/Model/ColumnInfo.cs
index b6fe08f6ff..490d5913b9 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ColumnInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ColumnInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.06
 
-using System;
 using System.Diagnostics;
 using System.Globalization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Model/ColumnInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/ColumnInfoCollection.cs
index 3666c2eba5..00e7a07263 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ColumnInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ColumnInfoCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.12.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/ColumnInfoRef.cs b/Orm/Xtensive.Orm/Orm/Model/ColumnInfoRef.cs
index 5e5c1856cd..28d7ecbdb9 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ColumnInfoRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ColumnInfoRef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.09.21
 
-using System;
 using System.Diagnostics;
 using System.Globalization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Model/DatabaseInfo.cs b/Orm/Xtensive.Orm/Orm/Model/DatabaseInfo.cs
index c10e000bea..d2880f7f75 100644
--- a/Orm/Xtensive.Orm/Orm/Model/DatabaseInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/DatabaseInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/DomainModel.cs b/Orm/Xtensive.Orm/Orm/Model/DomainModel.cs
index 763a54eaed..98b4506fc0 100644
--- a/Orm/Xtensive.Orm/Orm/Model/DomainModel.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/DomainModel.cs
@@ -4,9 +4,6 @@
 // Created by: Alex Ustinov
 // Created:    2007.07.11
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/DomainModelExtensions.cs b/Orm/Xtensive.Orm/Orm/Model/DomainModelExtensions.cs
index 27d267c3a4..0fe076263d 100644
--- a/Orm/Xtensive.Orm/Orm/Model/DomainModelExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/DomainModelExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.24
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Sorting;
 using Xtensive.Orm.Model.Stored;
diff --git a/Orm/Xtensive.Orm/Orm/Model/FieldAttributes.cs b/Orm/Xtensive.Orm/Orm/Model/FieldAttributes.cs
index 945187c174..fa2eed329b 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FieldAttributes.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FieldAttributes.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2007.09.29
 
-using System;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/FieldInfo.cs b/Orm/Xtensive.Orm/Orm/Model/FieldInfo.cs
index c7def21ad1..567c38b031 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FieldInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FieldInfo.cs
@@ -4,10 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2007.09.10
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Model/FieldInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/FieldInfoCollection.cs
index 70e20bc35d..18019cd53b 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FieldInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FieldInfoCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.11.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/FieldInfoRef.cs b/Orm/Xtensive.Orm/Orm/Model/FieldInfoRef.cs
index 77f6541816..4e78b4e8d5 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FieldInfoRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FieldInfoRef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.22
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/FieldMap.cs b/Orm/Xtensive.Orm/Orm/Model/FieldMap.cs
index 3ee5f37c6a..505b751228 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FieldMap.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FieldMap.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2007.12.27
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfo.cs b/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfo.cs
index 5331780d3d..f00148bcb5 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.18
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfoCollection.cs
index c0fcdc2f77..01c101a27c 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FullTextColumnInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.18
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfo.cs b/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfo.cs
index 0d043571b8..c837a66c55 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.23
 
-using System;
 
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfoCollection.cs
index c2c3894938..10e1a948ac 100644
--- a/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/FullTextIndexInfoCollection.cs
@@ -4,10 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2009.12.23
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/HierarchyInfo.cs b/Orm/Xtensive.Orm/Orm/Model/HierarchyInfo.cs
index 7ced941373..9cee87ae70 100644
--- a/Orm/Xtensive.Orm/Orm/Model/HierarchyInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/HierarchyInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.11
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/HierarchyInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/HierarchyInfoCollection.cs
index fe661448a1..6ce02daa90 100644
--- a/Orm/Xtensive.Orm/Orm/Model/HierarchyInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/HierarchyInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.11
 
-using System;
 
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/IndexAttributes.cs b/Orm/Xtensive.Orm/Orm/Model/IndexAttributes.cs
index d2542954c3..186ba1f311 100644
--- a/Orm/Xtensive.Orm/Orm/Model/IndexAttributes.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/IndexAttributes.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.23
 
-using System;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/IndexInfo.cs b/Orm/Xtensive.Orm/Orm/Model/IndexInfo.cs
index 569873d979..9716bbde5a 100644
--- a/Orm/Xtensive.Orm/Orm/Model/IndexInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/IndexInfo.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Ustinov
 // Created:    2007.07.10
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Model/IndexInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/IndexInfoCollection.cs
index a5988b8ec3..ffb2c8b208 100644
--- a/Orm/Xtensive.Orm/Orm/Model/IndexInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/IndexInfoCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.05.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/IndexInfoRef.cs b/Orm/Xtensive.Orm/Orm/Model/IndexInfoRef.cs
index 12ad5cd538..e5af3281ca 100644
--- a/Orm/Xtensive.Orm/Orm/Model/IndexInfoRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/IndexInfoRef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.22
 
-using System;
 using System.Diagnostics;
 
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Model/Internals/TypePairComparer.cs b/Orm/Xtensive.Orm/Orm/Model/Internals/TypePairComparer.cs
index 1dad31984c..361a8a5286 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Internals/TypePairComparer.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Internals/TypePairComparer.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.03.17
 
-using System.Collections.Generic;
 using Xtensive.Comparison;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/KeyField.cs b/Orm/Xtensive.Orm/Orm/Model/KeyField.cs
index 1856846ce9..b03727ee04 100644
--- a/Orm/Xtensive.Orm/Orm/Model/KeyField.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/KeyField.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.12.28
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/KeyInfo.cs b/Orm/Xtensive.Orm/Orm/Model/KeyInfo.cs
index a3ef2a6fad..d3245a9344 100644
--- a/Orm/Xtensive.Orm/Orm/Model/KeyInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/KeyInfo.cs
@@ -4,10 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2009.02.13
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/MappedNode.cs b/Orm/Xtensive.Orm/Orm/Model/MappedNode.cs
index a3a75ddf5e..41f16af2f1 100644
--- a/Orm/Xtensive.Orm/Orm/Model/MappedNode.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/MappedNode.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.01.13
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/ModelVisitor.cs b/Orm/Xtensive.Orm/Orm/Model/ModelVisitor.cs
index 71ecc7dedd..8f178f3dbb 100644
--- a/Orm/Xtensive.Orm/Orm/Model/ModelVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/ModelVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.02
 
-using System;
 
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/Node.cs b/Orm/Xtensive.Orm/Orm/Model/Node.cs
index 5dd5521a68..fb2a950a32 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Node.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Node.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.25
 
-using System;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Model/NodeCollection.cs b/Orm/Xtensive.Orm/Orm/Model/NodeCollection.cs
index 687dda668b..8742a1830e 100644
--- a/Orm/Xtensive.Orm/Orm/Model/NodeCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/NodeCollection.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.07.30
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Model/OnRemoveAction.cs b/Orm/Xtensive.Orm/Orm/Model/OnRemoveAction.cs
index 0dcdf8fec0..80f7c63fca 100644
--- a/Orm/Xtensive.Orm/Orm/Model/OnRemoveAction.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/OnRemoveAction.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.06.24
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/PartialIndexFilterInfo.cs b/Orm/Xtensive.Orm/Orm/Model/PartialIndexFilterInfo.cs
index 8de3e95f09..72b8b8c49c 100644
--- a/Orm/Xtensive.Orm/Orm/Model/PartialIndexFilterInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/PartialIndexFilterInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.10
 
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/SchemaMappedNode.cs b/Orm/Xtensive.Orm/Orm/Model/SchemaMappedNode.cs
index dd4424799f..cf4fdc8740 100644
--- a/Orm/Xtensive.Orm/Orm/Model/SchemaMappedNode.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/SchemaMappedNode.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.10
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/SequenceInfo.cs b/Orm/Xtensive.Orm/Orm/Model/SequenceInfo.cs
index 5ac313f09e..7f6f5c210e 100644
--- a/Orm/Xtensive.Orm/Orm/Model/SequenceInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/SequenceInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.09
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ConverterToStoredModel.cs b/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ConverterToStoredModel.cs
index 3f60975d46..9dffb9ef1f 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ConverterToStoredModel.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ConverterToStoredModel.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.24
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Reflection;
 
 namespace Xtensive.Orm.Model.Stored
diff --git a/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ReferenceUpdater.cs b/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ReferenceUpdater.cs
index c93537c171..cf58515a64 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ReferenceUpdater.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Stored/Internals/ReferenceUpdater.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Model/Stored/StoredAssociationInfo.cs b/Orm/Xtensive.Orm/Orm/Model/Stored/StoredAssociationInfo.cs
index 27362e76a9..d725471859 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Stored/StoredAssociationInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Stored/StoredAssociationInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.22
 
-using System;
 using System.ComponentModel;
 using System.Xml.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Model/Stored/StoredFieldInfo.cs b/Orm/Xtensive.Orm/Orm/Model/Stored/StoredFieldInfo.cs
index 3a9e7cc95c..31a9b61e86 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Stored/StoredFieldInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Stored/StoredFieldInfo.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.22
 
-using System.Collections.Generic;
 using System.ComponentModel;
-using System.Linq;
 using System.Xml.Serialization;
-using System;
 using Xtensive.Collections;
 
 namespace Xtensive.Orm.Model.Stored
diff --git a/Orm/Xtensive.Orm/Orm/Model/Stored/StoredTypeInfo.cs b/Orm/Xtensive.Orm/Orm/Model/Stored/StoredTypeInfo.cs
index b8ba8fa3e9..4205b43ada 100644
--- a/Orm/Xtensive.Orm/Orm/Model/Stored/StoredTypeInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/Stored/StoredTypeInfo.cs
@@ -4,10 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.05.22
 
-using System;
 using System.ComponentModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Xml.Serialization;
 
 namespace Xtensive.Orm.Model.Stored
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeAttributes.cs b/Orm/Xtensive.Orm/Orm/Model/TypeAttributes.cs
index 0335e53d10..bc25dd50b4 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeAttributes.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeAttributes.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitry Maximov
 // Created:    2007.09.29
 
-using System;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeDiscriminatorMap.cs b/Orm/Xtensive.Orm/Orm/Model/TypeDiscriminatorMap.cs
index c789a14252..3c8d9d5361 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeDiscriminatorMap.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeDiscriminatorMap.cs
@@ -4,11 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2009.11.26
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
-using System.Linq;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeIdRegistry.cs b/Orm/Xtensive.Orm/Orm/Model/TypeIdRegistry.cs
index 88eced72cf..ce72e5b847 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeIdRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeIdRegistry.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Model
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeIndexInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/TypeIndexInfoCollection.cs
index 2911d4b34c..1b7d7f54e9 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeIndexInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeIndexInfoCollection.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2007.11.26
 
-using System;
 using System.Diagnostics;
-using System.Linq;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeInfo.cs b/Orm/Xtensive.Orm/Orm/Model/TypeInfo.cs
index e98d4150e2..1b7f5bf0b7 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeInfo.cs
@@ -4,13 +4,10 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.27
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
-using System.Linq;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Model/TypeInfoCollection.cs
index 00105cbb1c..d2a69ef403 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeInfoCollection.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Model/TypeInfoRef.cs b/Orm/Xtensive.Orm/Orm/Model/TypeInfoRef.cs
index 5e243b8b38..dda00533b3 100644
--- a/Orm/Xtensive.Orm/Orm/Model/TypeInfoRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/TypeInfoRef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.22
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/NotifyChangedOptions.cs b/Orm/Xtensive.Orm/Orm/NotifyChangedOptions.cs
index 0baf66b9e0..2ab63d0238 100644
--- a/Orm/Xtensive.Orm/Orm/NotifyChangedOptions.cs
+++ b/Orm/Xtensive.Orm/Orm/NotifyChangedOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.03
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Operation.cs b/Orm/Xtensive.Orm/Orm/Operation.cs
index 3ff190b0f0..3baa0fdf7a 100644
--- a/Orm/Xtensive.Orm/Orm/Operation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operation.cs
@@ -4,11 +4,8 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.19
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Orm.Operations;
diff --git a/Orm/Xtensive.Orm/Orm/OperationLog.cs b/Orm/Xtensive.Orm/Orm/OperationLog.cs
index 333a83a430..2adfb7b78c 100644
--- a/Orm/Xtensive.Orm/Orm/OperationLog.cs
+++ b/Orm/Xtensive.Orm/Orm/OperationLog.cs
@@ -4,9 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/OperationLogType.cs b/Orm/Xtensive.Orm/Orm/OperationLogType.cs
index 57f2811d49..dcdd55b9ff 100644
--- a/Orm/Xtensive.Orm/Orm/OperationLogType.cs
+++ b/Orm/Xtensive.Orm/Orm/OperationLogType.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.05
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntitiesRemoveOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntitiesRemoveOperation.cs
index 1f378137c3..383b68f58e 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntitiesRemoveOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntitiesRemoveOperation.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.25
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntityCreateOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntityCreateOperation.cs
index f65c759a27..c5a5df333e 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntityCreateOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntityCreateOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.25
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntityFieldOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntityFieldOperation.cs
index 9b1c67dca3..7eb2fd2bfd 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntityFieldOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntityFieldOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.19
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntityFieldSetOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntityFieldSetOperation.cs
index e8aa99d59d..a0349f8b99 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntityFieldSetOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntityFieldSetOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntityIdentifierType.cs b/Orm/Xtensive.Orm/Orm/Operations/EntityIdentifierType.cs
index 99e73d8cd7..270e42256f 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntityIdentifierType.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntityIdentifierType.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.07.28
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Operations
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntityInitializeOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntityInitializeOperation.cs
index 1d15fa9735..c615105d95 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntityInitializeOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntityInitializeOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.11
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntityOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntityOperation.cs
index 61437c70cd..c0ea48cc27 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntityOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntityOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 using System.Runtime.Serialization;
 using System.Security.Permissions;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntitySetClearOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntitySetClearOperation.cs
index 57f586d3a2..6da464a924 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntitySetClearOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntitySetClearOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.25
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemAddOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemAddOperation.cs
index 2b2b392a76..f5abc47f15 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemAddOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemAddOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.25
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemOperation.cs
index 3840c3e467..7bf4b445dc 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemRemoveOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemRemoveOperation.cs
index 6b905898f6..013acfc236 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemRemoveOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntitySetItemRemoveOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.25
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/EntitySetOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/EntitySetOperation.cs
index 0cebe22e46..80c0012d8f 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/EntitySetOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/EntitySetOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.20
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/Internals/OperationRegistrationScope.cs b/Orm/Xtensive.Orm/Orm/Operations/Internals/OperationRegistrationScope.cs
index 9b788a7b35..d9b3909b7f 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/Internals/OperationRegistrationScope.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/Internals/OperationRegistrationScope.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/KeyGenerateOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/KeyGenerateOperation.cs
index cbc3852cc4..4f6d0e1318 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/KeyGenerateOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/KeyGenerateOperation.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2010.02.15
 
-using System;
-using System.Linq;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/KeyOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/KeyOperation.cs
index 521f7c72fe..0dc07568b8 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/KeyOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/KeyOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/KeySetOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/KeySetOperation.cs
index 99bae45c05..20db5dd16a 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/KeySetOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/KeySetOperation.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.10
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Security;
@@ -13,7 +11,6 @@
 using Xtensive.Core;
 using Xtensive.Collections;
 
-using System.Linq;
 
 namespace Xtensive.Orm.Operations
 {
diff --git a/Orm/Xtensive.Orm/Orm/Operations/MethodCallOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/MethodCallOperation.cs
index 629f2632e6..ccc5cd4bee 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/MethodCallOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/MethodCallOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.23
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Operations/OperationCapturer.cs b/Orm/Xtensive.Orm/Orm/Operations/OperationCapturer.cs
index b76bbd4f12..4a513b05ab 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/OperationCapturer.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/OperationCapturer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.22
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Operations
diff --git a/Orm/Xtensive.Orm/Orm/Operations/OperationCompletedEventArgs.cs b/Orm/Xtensive.Orm/Orm/Operations/OperationCompletedEventArgs.cs
index 1934192ef8..e27713ee26 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/OperationCompletedEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/OperationCompletedEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.04
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/OperationEventArgs.cs b/Orm/Xtensive.Orm/Orm/Operations/OperationEventArgs.cs
index 016586ea66..7b877d6972 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/OperationEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/OperationEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.11.23
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/OperationExecutionContext.cs b/Orm/Xtensive.Orm/Orm/Operations/OperationExecutionContext.cs
index 7ed4bd4b4a..cc83e974ea 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/OperationExecutionContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/OperationExecutionContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.10.21
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/OperationRegistry.cs b/Orm/Xtensive.Orm/Orm/Operations/OperationRegistry.cs
index cc4e6b4d08..c52b7f539d 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/OperationRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/OperationRegistry.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.04
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Operations/OperationType.cs b/Orm/Xtensive.Orm/Orm/Operations/OperationType.cs
index c1d10ea3a8..9f47d85978 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/OperationType.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/OperationType.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.04
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Orm.Operations
diff --git a/Orm/Xtensive.Orm/Orm/Operations/ValidateVersionOperation.cs b/Orm/Xtensive.Orm/Orm/Operations/ValidateVersionOperation.cs
index b0244467c5..69d162059d 100644
--- a/Orm/Xtensive.Orm/Orm/Operations/ValidateVersionOperation.cs
+++ b/Orm/Xtensive.Orm/Orm/Operations/ValidateVersionOperation.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2010.02.19
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Persistent.cs b/Orm/Xtensive.Orm/Orm/Persistent.cs
index 3e48bca07f..d5855feb51 100644
--- a/Orm/Xtensive.Orm/Orm/Persistent.cs
+++ b/Orm/Xtensive.Orm/Orm/Persistent.cs
@@ -4,10 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.03
 
-using System;
-using System.Collections.Generic;
 using System.ComponentModel;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/PersistentFieldState.cs b/Orm/Xtensive.Orm/Orm/PersistentFieldState.cs
index df39dca520..defa6261a5 100644
--- a/Orm/Xtensive.Orm/Orm/PersistentFieldState.cs
+++ b/Orm/Xtensive.Orm/Orm/PersistentFieldState.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.18
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/PrefetchExtensions.cs b/Orm/Xtensive.Orm/Orm/PrefetchExtensions.cs
index ae54d56162..1005ab922d 100644
--- a/Orm/Xtensive.Orm/Orm/PrefetchExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/PrefetchExtensions.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.09.30
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Orm.Internals.Prefetch;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/PrefetchQuery.cs b/Orm/Xtensive.Orm/Orm/PrefetchQuery.cs
index c3c25ec4df..841f465a34 100644
--- a/Orm/Xtensive.Orm/Orm/PrefetchQuery.cs
+++ b/Orm/Xtensive.Orm/Orm/PrefetchQuery.cs
@@ -2,12 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Linq.Expressions;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Collections;
 using Xtensive.Orm.Internals.Prefetch;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/ChainingSessionHandler.cs b/Orm/Xtensive.Orm/Orm/Providers/ChainingSessionHandler.cs
index d375f1775b..1a6d185f15 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/ChainingSessionHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/ChainingSessionHandler.cs
@@ -4,14 +4,12 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.07.06
 
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Internals.Prefetch;
 using Xtensive.Orm.Model;
 using Xtensive.Tuples;
+using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/BatchingCommandProcessor.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/BatchingCommandProcessor.cs
index f2bad23093..6420cb4aae 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/BatchingCommandProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/BatchingCommandProcessor.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.20
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/Command.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/Command.cs
index bfdeb15625..a197b4459a 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/Command.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/Command.cs
@@ -4,11 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandFactory.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandFactory.cs
index 208a6c89aa..00c813586f 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandFactory.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandPart.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandPart.cs
index 301f6b3cc0..5d6d89cdea 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandPart.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandPart.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessor.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessor.cs
index 7c2e3a5d65..d36b26074c 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessor.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.20
 
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessorContext.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessorContext.cs
index 13537473cc..df78d8e665 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessorContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandProcessorContext.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2019.07.12
 
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/DataReader.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/DataReader.cs
index 410e31b2e6..63e4cf50c5 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/DataReader.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/DataReader.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Tuple = Xtensive.Tuples.Tuple;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SimpleCommandProcessor.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SimpleCommandProcessor.cs
index 64feb48571..34d7916bc1 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SimpleCommandProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SimpleCommandProcessor.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.20
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlLoadTask.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlLoadTask.cs
index ecde7725d0..3d08b77b38 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlLoadTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlLoadTask.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.21
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlPersistTask.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlPersistTask.cs
index 42c319b6fe..6c76bb0393 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlPersistTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/SqlPersistTask.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.21
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CommandWithDataReader.cs b/Orm/Xtensive.Orm/Orm/Providers/CommandWithDataReader.cs
index 67f40513ca..a3d167455e 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CommandWithDataReader.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CommandWithDataReader.cs
@@ -4,9 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.01
 
-using System;
 using System.Data.Common;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CompilationService.cs b/Orm/Xtensive.Orm/Orm/Providers/CompilationService.cs
index 9c44c2c5e8..e6c329dbcf 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CompilationService.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CompilationService.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.04
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Compilation;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/CompilerConfiguration.cs b/Orm/Xtensive.Orm/Orm/Providers/CompilerConfiguration.cs
index 46c2649f3a..3a77050ce3 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/CompilerConfiguration.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/CompilerConfiguration.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.26
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/DbCommandExtensions.cs b/Orm/Xtensive.Orm/Orm/Providers/DbCommandExtensions.cs
index 436349f46e..dea94acf01 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/DbCommandExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/DbCommandExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.10.14
 
-using System;
 using System.Data.Common;
 using System.Text;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/DbDataReaderAccessor.cs b/Orm/Xtensive.Orm/Orm/Providers/DbDataReaderAccessor.cs
index 40b94bde08..0483266a77 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/DbDataReaderAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/DbDataReaderAccessor.cs
@@ -4,9 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.30
 
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Linq;
 using Xtensive.Tuples;
 using Xtensive.Sql;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/DomainHandler.cs b/Orm/Xtensive.Orm/Orm/Providers/DomainHandler.cs
index 6e7824d522..e7f345a0ec 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/DomainHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/DomainHandler.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.05.19
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Linq.MemberCompilation;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/EnumerationContext.cs b/Orm/Xtensive.Orm/Orm/Providers/EnumerationContext.cs
index 5e76e5639f..1f78654b55 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/EnumerationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/EnumerationContext.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.30
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Linq.Materialization;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/BooleanExpressionConverter.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/BooleanExpressionConverter.cs
index 64fa94bb9a..80b3d60ca0 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/BooleanExpressionConverter.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/BooleanExpressionConverter.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.17
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Reflection;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.Helpers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.Helpers.cs
index ebfdf8b362..8bae309c36 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.Helpers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.Helpers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.09.26
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.cs
index 948ec51181..6c4b9da32f 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionProcessor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.09.05
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationContext.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationContext.cs
index f0ba3e8bab..e150ee3175 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationContext.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.09.18
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationHelpers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationHelpers.cs
index 5d20d0792f..89127ff85f 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationHelpers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/ExpressionTranslationHelpers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.09.18
 
-using System;
 using Xtensive.Reflection;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateOnlyCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateOnlyCompilers.cs
index 83dd54d2a7..6c67e75ee2 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateOnlyCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateOnlyCompilers.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeCompilers.cs
index cadfe870f3..531377ece4 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.14
 
-using System;
 using Xtensive.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeOffsetCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeOffsetCompilers.cs
index 8b816fb71a..1f7bf80d88 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeOffsetCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DateTimeOffsetCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2013.11.25
 
-using System;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 using Operator = Xtensive.Reflection.WellKnown.Operator;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DecimalCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DecimalCompilers.cs
index 0aa864fadd..efd83f1fa9 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DecimalCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/DecimalCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.18
 
-using System;
 using Xtensive.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/EnumCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/EnumCompilers.cs
index 527eec677b..735362deb0 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/EnumCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/EnumCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.07.23
 
-using System;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/GuidCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/GuidCompilers.cs
index c2d04dea70..7bb0b3097d 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/GuidCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/GuidCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.10
 
-using System;
 using Xtensive.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/MathCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/MathCompilers.cs
index da49f46f37..93431e2164 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/MathCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/MathCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.14
 
-using System;
 using Xtensive.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NullableCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NullableCompilers.cs
index c531a8a9a9..0bf7e9a8d1 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NullableCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NullableCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.20
 
-using System;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NumericCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NumericCompilers.cs
index 556753478d..8391454842 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NumericCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/NumericCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.15
 
-using System;
 using Xtensive.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/StringCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/StringCompilers.cs
index 9fd23702ab..f1dc207c40 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/StringCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/StringCompilers.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.13
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeOnlyCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeOnlyCompilers.cs
index 36fa6664a6..4f703392aa 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeOnlyCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeOnlyCompilers.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Reflection;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeSpanCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeSpanCompilers.cs
index f98d916419..c086297145 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeSpanCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/TimeSpanCompilers.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.24
 
-using System;
 using Xtensive.Reflection;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbConversionsCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbConversionsCompilers.cs
index 8c82953e12..8154d7e745 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbConversionsCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbConversionsCompilers.cs
@@ -4,9 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2010.11.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Linq;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbDateAndTimeCompilers.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbDateAndTimeCompilers.cs
index c87cf8bc98..2437800872 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbDateAndTimeCompilers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/MemberCompilers/VbDateAndTimeCompilers.cs
@@ -4,9 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2010.11.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Xtensive.Linq;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Expressions/QueryParameterIdentity.cs b/Orm/Xtensive.Orm/Orm/Providers/Expressions/QueryParameterIdentity.cs
index 344c1a0781..f0c8d802a9 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Expressions/QueryParameterIdentity.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Expressions/QueryParameterIdentity.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.17
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/GeneralPurposeExtensions.cs b/Orm/Xtensive.Orm/Orm/Providers/GeneralPurposeExtensions.cs
index 155fc2a0f4..df58840a7d 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/GeneralPurposeExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/GeneralPurposeExtensions.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Compiler;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/HandlerFactory.cs b/Orm/Xtensive.Orm/Orm/Providers/HandlerFactory.cs
index 3257e05bd0..241404e206 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/HandlerFactory.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/HandlerFactory.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.06.02
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IDirectSqlService.cs b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IDirectSqlService.cs
index 7fccf380ff..44cb5b2299 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IDirectSqlService.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IDirectSqlService.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.08
 
-using System;
 using System.Data.Common;
 using Xtensive.Orm.Services;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IPersistDescriptors.cs b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IPersistDescriptors.cs
index 020c2d32da..dd702b66ca 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IPersistDescriptors.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IPersistDescriptors.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
-using System;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IProviderExecutor.cs b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IProviderExecutor.cs
index d4597cc6bf..3b8ae510a4 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IProviderExecutor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IProviderExecutor.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.30
 
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IQueryRequest.cs b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IQueryRequest.cs
index df4ee32c71..05d40dafe1 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IQueryRequest.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IQueryRequest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.25
 
-using System.Collections.Generic;
 using Xtensive.Sql.Compiler;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/ISqlExecutor.cs b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/ISqlExecutor.cs
index ec024c3a0f..ba381d1fdb 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/ISqlExecutor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/ISqlExecutor.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.29
 
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Sql;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IStorageSequenceAccessor.cs b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IStorageSequenceAccessor.cs
index 01bc82f157..407b34e41a 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IStorageSequenceAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Interfaces/IStorageSequenceAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.09
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/MappingResolver.cs b/Orm/Xtensive.Orm/Orm/Providers/MappingResolver.cs
index 0515850891..d20cab1e43 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/MappingResolver.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/MappingResolver.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.06
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/ModelMapping.cs b/Orm/Xtensive.Orm/Orm/Providers/ModelMapping.cs
index 4e3f660c7d..6bc97e1167 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/ModelMapping.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/ModelMapping.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.23
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/MultidatabaseMappingResolver.cs b/Orm/Xtensive.Orm/Orm/Providers/MultidatabaseMappingResolver.cs
index 984cf9a6cc..0983a9092d 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/MultidatabaseMappingResolver.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/MultidatabaseMappingResolver.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/MultischemaMappingResolver.cs b/Orm/Xtensive.Orm/Orm/Providers/MultischemaMappingResolver.cs
index 19812c160e..a96c367037 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/MultischemaMappingResolver.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/MultischemaMappingResolver.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/NameBuilder.cs b/Orm/Xtensive.Orm/Orm/Providers/NameBuilder.cs
index d82f34614e..40495917a9 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/NameBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/NameBuilder.cs
@@ -4,10 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.27
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Security.Cryptography;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/NullSearchConditionCompiler.cs b/Orm/Xtensive.Orm/Orm/Providers/NullSearchConditionCompiler.cs
index 8b2e85639e..ce750a5863 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/NullSearchConditionCompiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/NullSearchConditionCompiler.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.12.08
 
-using System;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/PartialIndexFilterCompiler.cs b/Orm/Xtensive.Orm/Orm/Providers/PartialIndexFilterCompiler.cs
index 0d0f5ea5c5..1af64513e5 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/PartialIndexFilterCompiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/PartialIndexFilterCompiler.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.07.18
 
-using System.Linq;
 using Xtensive.Orm.Model;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Persister.cs b/Orm/Xtensive.Orm/Orm/Providers/Persister.cs
index 6d6733d023..123dcb4227 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Persister.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Persister.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.04.02
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/ProviderAttribute.cs b/Orm/Xtensive.Orm/Orm/Providers/ProviderAttribute.cs
index 4ed7854694..6200533729 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/ProviderAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/ProviderAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.01.21
 
-using System;
 using Xtensive.Sql;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/ProviderFeatures.cs b/Orm/Xtensive.Orm/Orm/Providers/ProviderFeatures.cs
index 91deae7dc7..457e4ec565 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/ProviderFeatures.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/ProviderFeatures.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.28
 
-using System;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/ProviderInfo.cs b/Orm/Xtensive.Orm/Orm/Providers/ProviderInfo.cs
index d9169a3560..5658df9c52 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/ProviderInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/ProviderInfo.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/ProviderInfoBuilder.cs b/Orm/Xtensive.Orm/Orm/Providers/ProviderInfoBuilder.cs
index 61c2da2919..519fe12e04 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/ProviderInfoBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/ProviderInfoBuilder.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.11
 
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/ParameterBinding.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/ParameterBinding.cs
index aa9a06d868..11db15b453 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/ParameterBinding.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/ParameterBinding.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistParameterBinding.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistParameterBinding.cs
index 60032d0de0..0ebd79b341 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistParameterBinding.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistParameterBinding.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.25
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequest.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequest.cs
index 8f2581035f..51dfc53668 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequest.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequest.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.22
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilder.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilder.cs
index 59aa179a26..595bbe58a1 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.28
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderContext.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderContext.cs
index 921b18c3c1..a3d53b643e 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderContext.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.29
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderTask.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderTask.cs
index 0acabb0291..db97b70433 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/PersistRequestBuilderTask.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.29
 
-using System;
 using System.Collections;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryParameterBinding.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryParameterBinding.cs
index 4f6f21ad91..25ffa2c55d 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryParameterBinding.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryParameterBinding.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.25
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequest.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequest.cs
index 065ff56fb5..b41d7c6edb 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequest.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequest.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.08.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Sql.Compiler;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequestOptions.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequestOptions.cs
index 5c3c64379a..18278ef572 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequestOptions.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRequestOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRowFilterParameterBinding.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRowFilterParameterBinding.cs
index cac8d390b6..fc6c61f3ee 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRowFilterParameterBinding.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryRowFilterParameterBinding.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryTypeIdentifierParameterBinding.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryTypeIdentifierParameterBinding.cs
index b0b7705bd1..274066c131 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryTypeIdentifierParameterBinding.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/QueryTypeIdentifierParameterBinding.cs
@@ -3,7 +3,6 @@
 // See the License.txt file in the project root for more information.
 
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/Requests/UserQueryRequest.cs b/Orm/Xtensive.Orm/Orm/Providers/Requests/UserQueryRequest.cs
index 2f0264cf92..c53bc259d9 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/Requests/UserQueryRequest.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/Requests/UserQueryRequest.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.25
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Sql.Compiler;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SequenceQuery.cs b/Orm/Xtensive.Orm/Orm/Providers/SequenceQuery.cs
index 5f540cefa7..b544453544 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SequenceQuery.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SequenceQuery.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.07
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SequenceQueryBuilder.cs b/Orm/Xtensive.Orm/Orm/Providers/SequenceQueryBuilder.cs
index 6455e4a125..8d6340df80 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SequenceQueryBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SequenceQueryBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.07
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Fetching.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Fetching.cs
index 95a73e8d0e..1f6924a36d 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Fetching.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Fetching.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.19
 
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Internals.Prefetch;
 using Xtensive.Orm.Model;
 using TypeInfo = Xtensive.Orm.Model.TypeInfo;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs
index cc9b69fefa..5f427d69e0 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.19
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.StateManagement.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.StateManagement.cs
index 11ace63c66..59c7ec7c43 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.StateManagement.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.StateManagement.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.19
 
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Transactions.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Transactions.cs
index fc0078c559..c26020d210 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Transactions.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.Transactions.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.19
 
-using System.Threading;
-using System.Threading.Tasks;
 
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs
index b6ac66b3b8..6fb8bafb91 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs
@@ -4,11 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2008.05.19
 
-using System;
-using System.Collections.Generic;
 using System.Data;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.IoC;
 using Xtensive.Orm.Internals;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SimpleMappingResolver.cs b/Orm/Xtensive.Orm/Orm/Providers/SimpleMappingResolver.cs
index fdd9c8d25f..5baec3094f 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SimpleMappingResolver.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SimpleMappingResolver.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Sql;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Aggregate.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Aggregate.cs
index b2612ffc8a..37f46cc8b8 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Aggregate.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Aggregate.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 using Xtensive.Orm.Rse;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Apply.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Apply.cs
index 80b5fd0907..de4cd088f3 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Apply.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Apply.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Helpers.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Helpers.cs
index f39c842178..b770995ea0 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Helpers.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Helpers.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Rse;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Include.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Include.cs
index 10d388a018..9da5c7c769 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Include.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Include.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Index.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Index.cs
index abf2bf3795..8006b8dd7a 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Index.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Index.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.NotSupported.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.NotSupported.cs
index 6d6312b878..b7cd364c87 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.NotSupported.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.NotSupported.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
 using Xtensive.Orm.Rse.Providers;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Paging.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Paging.cs
index b569109076..858fe41e35 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Paging.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Paging.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.cs
index 6ccd517770..3f17a92de3 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.cs
@@ -4,9 +4,6 @@
 // Created by: Vakhtina Elena
 // Created:    2009.02.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlExecutor.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlExecutor.cs
index e81f6f1cf4..d6eab19a0b 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlExecutor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlExecutor.cs
@@ -4,12 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.29
 
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlIncludeProvider.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlIncludeProvider.cs
index 2cd816488a..1df4f968ee 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlIncludeProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlIncludeProvider.cs
@@ -4,14 +4,9 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Orm.Rse.Providers;
-using System.Threading.Tasks;
-using System.Threading;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlProvider.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlProvider.cs
index 227990d31b..d6f42027c1 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlProvider.cs
@@ -4,13 +4,10 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.11
 
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 using Xtensive.Orm.Rse.Providers;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlProviderPreparer.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlProviderPreparer.cs
index 8504615137..02351b9073 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlProviderPreparer.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlProviderPreparer.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.29
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Rse;
 using Xtensive.Orm.Rse.Compilation;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlSelectProcessor.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlSelectProcessor.cs
index e8e098b63d..a7e9db6789 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlSelectProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlSelectProcessor.cs
@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Sql;
 using Xtensive.Sql.Ddl;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.Fetching.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.Fetching.cs
index d5069a9264..b190962d11 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.Fetching.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.Fetching.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.19
 
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Internals.Prefetch;
 using Xtensive.Orm.Model;
 using TypeInfo = Xtensive.Orm.Model.TypeInfo;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IDirectSqlService.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IDirectSqlService.cs
index d5e3b5788f..5fed3eb4e3 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IDirectSqlService.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IDirectSqlService.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.09
 
-using System;
 using System.Data.Common;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IProviderExecutor.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IProviderExecutor.cs
index a2a2a85d62..a93700dbda 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IProviderExecutor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IProviderExecutor.cs
@@ -4,10 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.02.09
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.cs
index 99cfd40aad..903fc75995 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.cs
@@ -4,11 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2008.05.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.IoC;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlStoreProvider.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlStoreProvider.cs
index a71278390b..cac333e99b 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlStoreProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlStoreProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.05
 
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Rse.Providers;
 
 namespace Xtensive.Orm.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SqlTemporaryDataProvider.cs b/Orm/Xtensive.Orm/Orm/Providers/SqlTemporaryDataProvider.cs
index c3415d52c5..5380f638ea 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SqlTemporaryDataProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SqlTemporaryDataProvider.cs
@@ -4,14 +4,10 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.13
 
-using System;
 using Xtensive.Core;
-using System.Collections.Generic;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Orm.Rse.Providers;
-using System.Threading.Tasks;
-using System.Threading;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.Operations.cs b/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.Operations.cs
index d3eaf5b036..be74325211 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.Operations.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.Operations.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.14
 
-using System;
 using System.Data;
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Configuration;
 using Xtensive.Sql;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.ValueTypeMapping.cs b/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.ValueTypeMapping.cs
index 2d10f9878c..e0009cee6c 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.ValueTypeMapping.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.ValueTypeMapping.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.14
 
-using System;
 using Xtensive.Sql;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.cs b/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.cs
index 363078b2d5..5c87a33ff3 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/StorageDriver.cs
@@ -4,12 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.14
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/StorageExceptionBuilder.cs b/Orm/Xtensive.Orm/Orm/Providers/StorageExceptionBuilder.cs
index ebb178a634..8750c26230 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/StorageExceptionBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/StorageExceptionBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.25
 
-using System;
-using System.Linq;
 using System.Text;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/StorageSequenceAccessor.cs b/Orm/Xtensive.Orm/Orm/Providers/StorageSequenceAccessor.cs
index b8e44781ef..c624c812a0 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/StorageSequenceAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/StorageSequenceAccessor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.09.13
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableDescriptor.cs b/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableDescriptor.cs
index 85b8d49854..45bdbcfced 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableDescriptor.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableDescriptor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.12
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Tuples;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableManager.cs b/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableManager.cs
index f369193e51..e1c0d6cac8 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableManager.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableManager.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableStateRegistry.cs b/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableStateRegistry.cs
index 4752a0a125..6429d198e3 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableStateRegistry.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableStateRegistry.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.12
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Query.cs b/Orm/Xtensive.Orm/Orm/Query.cs
index 2a399d777d..0c630441f5 100644
--- a/Orm/Xtensive.Orm/Orm/Query.cs
+++ b/Orm/Xtensive.Orm/Orm/Query.cs
@@ -4,13 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2009.07.27
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
 using Xtensive.Orm.FullTextSearchCondition.Nodes;
diff --git a/Orm/Xtensive.Orm/Orm/QueryEndpoint.cs b/Orm/Xtensive.Orm/Orm/QueryEndpoint.cs
index 19c56ad487..03402eefa7 100644
--- a/Orm/Xtensive.Orm/Orm/QueryEndpoint.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryEndpoint.cs
@@ -2,13 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.FullTextSearchCondition.Interfaces;
diff --git a/Orm/Xtensive.Orm/Orm/QueryEventArgs.cs b/Orm/Xtensive.Orm/Orm/QueryEventArgs.cs
index b95eaa36cd..2446970a6c 100644
--- a/Orm/Xtensive.Orm/Orm/QueryEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryEventArgs.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Linq.Expressions;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/QueryResult.cs b/Orm/Xtensive.Orm/Orm/QueryResult.cs
index 7a83cc87ea..94017ed401 100644
--- a/Orm/Xtensive.Orm/Orm/QueryResult.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryResult.cs
@@ -2,9 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using JetBrains.Annotations;
 using Xtensive.Orm.Linq.Materialization;
 
diff --git a/Orm/Xtensive.Orm/Orm/QueryResultExtensions.cs b/Orm/Xtensive.Orm/Orm/QueryResultExtensions.cs
index fb7a99d9d4..5a040c937a 100644
--- a/Orm/Xtensive.Orm/Orm/QueryResultExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryResultExtensions.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Linq;
 using Xtensive.Orm.Linq.Expressions;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/QueryRootBuilder.cs b/Orm/Xtensive.Orm/Orm/QueryRootBuilder.cs
index b35e575d7e..6364acc2a0 100644
--- a/Orm/Xtensive.Orm/Orm/QueryRootBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryRootBuilder.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.23
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/QueryableExtensions.Async.cs b/Orm/Xtensive.Orm/Orm/QueryableExtensions.Async.cs
index 8338ef715d..b120e1d0f5 100644
--- a/Orm/Xtensive.Orm/Orm/QueryableExtensions.Async.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryableExtensions.Async.cs
@@ -2,13 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Linq;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/QueryableExtensions.cs b/Orm/Xtensive.Orm/Orm/QueryableExtensions.cs
index 250ff83725..12521140fe 100644
--- a/Orm/Xtensive.Orm/Orm/QueryableExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/QueryableExtensions.cs
@@ -4,15 +4,10 @@
 // Created by: Alexey Gamzov
 // Created:    2009.05.06
 
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Runtime.CompilerServices;
-using System.Threading;
-using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Record.cs b/Orm/Xtensive.Orm/Orm/Record.cs
index 039867ca69..2865a735e4 100644
--- a/Orm/Xtensive.Orm/Orm/Record.cs
+++ b/Orm/Xtensive.Orm/Orm/Record.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.12.30
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Tuples;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/RecycledFieldDefinition.cs b/Orm/Xtensive.Orm/Orm/RecycledFieldDefinition.cs
index 4ff6cf1be6..413d2a9d5b 100644
--- a/Orm/Xtensive.Orm/Orm/RecycledFieldDefinition.cs
+++ b/Orm/Xtensive.Orm/Orm/RecycledFieldDefinition.cs
@@ -4,7 +4,6 @@
 // Created by: Andrey Turkov
 // Created:    2013.08.21
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Ref.cs b/Orm/Xtensive.Orm/Orm/Ref.cs
index eb468d5cad..1ce5c33d9e 100644
--- a/Orm/Xtensive.Orm/Orm/Ref.cs
+++ b/Orm/Xtensive.Orm/Orm/Ref.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.15
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Security;
diff --git a/Orm/Xtensive.Orm/Orm/ReferenceFinder.cs b/Orm/Xtensive.Orm/Orm/ReferenceFinder.cs
index 090eb40d1f..26aede8065 100644
--- a/Orm/Xtensive.Orm/Orm/ReferenceFinder.cs
+++ b/Orm/Xtensive.Orm/Orm/ReferenceFinder.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/ReferenceInfo.cs b/Orm/Xtensive.Orm/Orm/ReferenceInfo.cs
index 254f89a75f..cba910f6f1 100644
--- a/Orm/Xtensive.Orm/Orm/ReferenceInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/ReferenceInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.10
 
-using System;
 
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/AggregateColumn.cs b/Orm/Xtensive.Orm/Orm/Rse/AggregateColumn.cs
index 0a3708fbae..6b2283fb33 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/AggregateColumn.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/AggregateColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.11
 
-using System;
 
 namespace Xtensive.Orm.Rse
 {
diff --git a/Orm/Xtensive.Orm/Orm/Rse/AggregateColumnDescriptor.cs b/Orm/Xtensive.Orm/Orm/Rse/AggregateColumnDescriptor.cs
index d01818cb54..8ef0416754 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/AggregateColumnDescriptor.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/AggregateColumnDescriptor.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.11
 
-using System;
 
 using Xtensive.Orm.Rse;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/ApplyParameter.cs b/Orm/Xtensive.Orm/Orm/Rse/ApplyParameter.cs
index bbcffc9655..51355de3db 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/ApplyParameter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/ApplyParameter.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.15
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Xml.Serialization;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumn.cs b/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumn.cs
index 3c00160621..687466dee3 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumn.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.09
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumnDescriptor.cs b/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumnDescriptor.cs
index 22f2a63c65..56ae3f49c4 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumnDescriptor.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/CalculatedColumnDescriptor.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.09
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Column.cs b/Orm/Xtensive.Orm/Orm/Rse/Column.cs
index fad40cca10..389aa36b28 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Column.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Column.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.09
 
-using System;
 
 
 namespace Xtensive.Orm.Rse
diff --git a/Orm/Xtensive.Orm/Orm/Rse/ColumnCollection.cs b/Orm/Xtensive.Orm/Orm/Rse/ColumnCollection.cs
index fafdc6fe21..b5a3aa9180 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/ColumnCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/ColumnCollection.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2007.09.24
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/ColumnGroupCollection.cs b/Orm/Xtensive.Orm/Orm/Rse/ColumnGroupCollection.cs
index 6bd6d03bd7..bcbbd3801f 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/ColumnGroupCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/ColumnGroupCollection.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Kofman
 // Created:    2008.08.07
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/CompilableProviderExtensions.cs b/Orm/Xtensive.Orm/Orm/Rse/CompilableProviderExtensions.cs
index 3d98832818..28e844c78e 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/CompilableProviderExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/CompilableProviderExtensions.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.08
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Comparison;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Compilation/Compiler.cs b/Orm/Xtensive.Orm/Orm/Rse/Compilation/Compiler.cs
index fd8e92e4ec..8c26d21e20 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Compilation/Compiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Compilation/Compiler.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Rse.Providers;
 
 namespace Xtensive.Orm.Rse.Compilation
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePostCompiler.cs b/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePostCompiler.cs
index 0c781c76bc..a155935bca 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePostCompiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePostCompiler.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.01.29
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Rse.Providers;
 
 namespace Xtensive.Orm.Rse.Compilation
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePreCompiler.cs b/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePreCompiler.cs
index 9af56d9427..14c50730a6 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePreCompiler.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Compilation/CompositePreCompiler.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.03.30
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Rse.Providers;
 
 namespace Xtensive.Orm.Rse.Compilation
diff --git a/Orm/Xtensive.Orm/Orm/Rse/MappedColumn.cs b/Orm/Xtensive.Orm/Orm/Rse/MappedColumn.cs
index 445a5f70b4..ecadb743bc 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/MappedColumn.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/MappedColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.09.21
 
-using System;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Rse
diff --git a/Orm/Xtensive.Orm/Orm/Rse/ProviderExtensions.cs b/Orm/Xtensive.Orm/Orm/Rse/ProviderExtensions.cs
index 3d82194768..f43b44ea60 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/ProviderExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/ProviderExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.09.13
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AggregateProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AggregateProvider.cs
index 28ea1b147a..e0a959974e 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AggregateProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AggregateProvider.cs
@@ -4,9 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.18
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AliasProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AliasProvider.cs
index 46eee42e6a..e22dd0093b 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AliasProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/AliasProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
 using Xtensive.Collections;
 
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ApplyProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ApplyProvider.cs
index 6dfaf0f40f..60fd0aa95a 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ApplyProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ApplyProvider.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.16
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/BinaryProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/BinaryProvider.cs
index c209d1e6cb..0d1a6c3ecd 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/BinaryProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/BinaryProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.22
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/CalculateProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/CalculateProvider.cs
index 8a8914d45c..403edfc08a 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/CalculateProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/CalculateProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.09.09
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Tuples.Transform;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ConcatProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ConcatProvider.cs
index 57a743908c..ba7ff79c8d 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ConcatProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ConcatProvider.cs
@@ -4,12 +4,9 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.01
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 
 
-using System.Linq;
 
 namespace Xtensive.Orm.Rse.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ContainsTableProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ContainsTableProvider.cs
index d1922125ec..0e23f6769c 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ContainsTableProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ContainsTableProvider.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/DistinctProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/DistinctProvider.cs
index f8fa7fbb38..81d3c21537 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/DistinctProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/DistinctProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.01.27
 
-using System;
 
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExceptProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExceptProvider.cs
index 455b8f3a31..c4e1d32521 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExceptProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExceptProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.01
 
-using System;
 using System.Diagnostics;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExistenceProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExistenceProvider.cs
index b279960563..5a7885622b 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExistenceProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/ExistenceProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.03.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FilterProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FilterProvider.cs
index dae6ee6d27..99d88b4acc 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FilterProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FilterProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FreeTextProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FreeTextProvider.cs
index c96b79b048..fc315bd477 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FreeTextProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/FreeTextProvider.cs
@@ -4,9 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.28
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IncludeProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IncludeProvider.cs
index 44d508b7b9..8a6d327e30 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IncludeProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IncludeProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.22
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using Xtensive.Core;
@@ -13,7 +11,6 @@
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Tuples.Transform;
-using System.Linq;
 using Xtensive.Reflection;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IndexProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IndexProvider.cs
index 9c3dee4177..8df1be81c0 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IndexProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IndexProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
 using Xtensive.Collections;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Rse.Compilation;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IntersectProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IntersectProvider.cs
index 540e26ccce..f4cfe1ea7e 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IntersectProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/IntersectProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.01
 
-using System;
 using System.Diagnostics;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/JoinProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/JoinProvider.cs
index 0d389d3e10..adaddced54 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/JoinProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/JoinProvider.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/LockProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/LockProvider.cs
index 17d7bcb97c..9cb655481f 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/LockProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/LockProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.24
 
-using System;
 
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/OrderProviderBase.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/OrderProviderBase.cs
index 661f8c9b4f..fb9f2e4906 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/OrderProviderBase.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/OrderProviderBase.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.08
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Comparison;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PagingProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PagingProvider.cs
index d917092ab7..e23e169c7d 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PagingProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PagingProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2011.03.24
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PredicateJoinProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PredicateJoinProvider.cs
index 2b24c1c3ee..23d478cc46 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PredicateJoinProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/PredicateJoinProvider.cs
@@ -4,10 +4,7 @@
 // Created by: Alexis Kochetov
 // Created:    2009.03.05
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RawProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RawProvider.cs
index 60a89bd075..75562f76ae 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RawProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RawProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.09
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RowNumberProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RowNumberProvider.cs
index 257440ae8e..35abdea2a1 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RowNumberProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/RowNumberProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.05
 
-using System;
 using Xtensive.Collections;
 using Xtensive.Reflection;
 using Xtensive.Tuples.Transform;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SeekProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SeekProvider.cs
index 1b9c1a34d9..cc5100874e 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SeekProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SeekProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.08.14
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SelectProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SelectProvider.cs
index 181e0054d4..0587aad8a0 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SelectProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SelectProvider.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SkipProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SkipProvider.cs
index 24a7a98d1e..9ae4a3223f 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SkipProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SkipProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.08.11
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SortProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SortProvider.cs
index 101bed0199..a2d7eb9c69 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SortProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/SortProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.04
 
-using System;
 using Xtensive.Collections;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/StoreProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/StoreProvider.cs
index b5ec29d67b..ce7c9b2e33 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/StoreProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/StoreProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.09.05
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TagProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TagProvider.cs
index 059fa632bf..d6e82dd805 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TagProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TagProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Edgar Isajanyan
 // Created:    2021.09.13
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TakeProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TakeProvider.cs
index cddccbdf8c..fd94a1f7a4 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TakeProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/TakeProvider.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.08.11
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/UnionProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/UnionProvider.cs
index 9b48469b24..e3b9a30dbe 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/UnionProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Compilable/UnionProvider.cs
@@ -4,12 +4,9 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.01
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 
 
-using System.Linq;
 
 namespace Xtensive.Orm.Rse.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProvider.cs
index 5d631a298e..0d7bed1780 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Rse.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProviderVisitor.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProviderVisitor.cs
index ccdced8d7f..4733a1338a 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProviderVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProviderVisitor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContext.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContext.cs
index 583ffba583..ac0709ee8e 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContext.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.16
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContextOptions.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContextOptions.cs
index e5fd6f9a87..5f8665527e 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContextOptions.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/EnumerationContextOptions.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.14
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Rse.Providers
 {
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Executable/ExecutableRawProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Executable/ExecutableRawProvider.cs
index a449e2cde3..72e5fff763 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Executable/ExecutableRawProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Executable/ExecutableRawProvider.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.08
 
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Providers;
 using Tuple = Xtensive.Tuples.Tuple;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider.cs
index 3fdfd41e48..3e3d184edd 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider.cs
@@ -4,10 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.07
 
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider{TOrigin}.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider{TOrigin}.cs
index 585b9648c7..77342a1438 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider{TOrigin}.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/ExecutableProvider{TOrigin}.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.13
 
-using System;
 
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/Provider.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/Provider.cs
index abab50d87c..9a52ce7a69 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/Provider.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/Provider.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.07.03
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/ProviderVisitor.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/ProviderVisitor.cs
index bb6f7f51fd..d03e165392 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/ProviderVisitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/ProviderVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.02.10
 
-using System;
 
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Providers/TagScope.cs b/Orm/Xtensive.Orm/Orm/Rse/Providers/TagScope.cs
index e6a1f28bc9..3d5edf5a3b 100755
--- a/Orm/Xtensive.Orm/Orm/Rse/Providers/TagScope.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Providers/TagScope.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Rse.Providers
diff --git a/Orm/Xtensive.Orm/Orm/Rse/RecordSetHeader.cs b/Orm/Xtensive.Orm/Orm/Rse/RecordSetHeader.cs
index d73985a447..3965e26087 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/RecordSetHeader.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/RecordSetHeader.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.09.13
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
@@ -13,7 +11,6 @@
 using Xtensive.Orm.Rse.Providers;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
-using System.Linq;
 using IndexInfo = Xtensive.Orm.Model.IndexInfo;
 
 namespace Xtensive.Orm.Rse
diff --git a/Orm/Xtensive.Orm/Orm/Rse/RecordSetReader.cs b/Orm/Xtensive.Orm/Orm/Rse/RecordSetReader.cs
index dc33df8e50..e1dabd7fad 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/RecordSetReader.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/RecordSetReader.cs
@@ -2,11 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Providers;
 using Xtensive.Orm.Rse.Providers;
 using EnumerationContext = Xtensive.Orm.Rse.Providers.EnumerationContext;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/RecordSetReaderExtensions.cs b/Orm/Xtensive.Orm/Orm/Rse/RecordSetReaderExtensions.cs
index 1635098c84..081d190606 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/RecordSetReaderExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/RecordSetReaderExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.06.09
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using EnumerationContext = Xtensive.Orm.Providers.EnumerationContext;
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/SystemColumn.cs b/Orm/Xtensive.Orm/Orm/Rse/SystemColumn.cs
index 95c1a744ea..da38fd1b99 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/SystemColumn.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/SystemColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.05
 
-using System;
 
 
 namespace Xtensive.Orm.Rse
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/ApplyProviderCorrector.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/ApplyProviderCorrector.cs
index d7061d2222..cda18d4bfb 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/ApplyProviderCorrector.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/ApplyProviderCorrector.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.15
 
-using System;
 using Xtensive.Orm.Rse.Compilation;
 using Xtensive.Orm.Rse.Providers;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/ColumnMappingInspector.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/ColumnMappingInspector.cs
index 23538116f9..9a22f0d0b0 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/ColumnMappingInspector.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/ColumnMappingInspector.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyFilterRewriter.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyFilterRewriter.cs
index bf68c109e9..ffdb178b6d 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyFilterRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyFilterRewriter.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.15
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyParameterSearcher.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyParameterSearcher.cs
index 72c7beae3d..641828cc8a 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyParameterSearcher.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyParameterSearcher.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.15
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyPredicateCollector.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyPredicateCollector.cs
index 5c04bd3bc1..38719fdc15 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyPredicateCollector.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyPredicateCollector.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyProviderCorrectorRewriter.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyProviderCorrectorRewriter.cs
index fd6084f9fc..af9ee5415f 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyProviderCorrectorRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyProviderCorrectorRewriter.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.15
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateProviderCollector.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateProviderCollector.cs
index 352b1eedfe..6a031976da 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateProviderCollector.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateProviderCollector.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateRelatedExpressionRewriter.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateRelatedExpressionRewriter.cs
index 5d082bd80b..acf114b242 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateRelatedExpressionRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CalculateRelatedExpressionRewriter.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.21
 
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CollectorHelper.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CollectorHelper.cs
index b949a88242..9f0b67157f 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CollectorHelper.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/CollectorHelper.cs
@@ -4,9 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/OrderingRewriter.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/OrderingRewriter.cs
index 97d2c9e023..b6dae24c6a 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/OrderingRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/OrderingRewriter.cs
@@ -4,12 +4,9 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.04.24
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Collections;
 using Xtensive.Orm.Rse.Providers;
-using System.Linq;
 
 namespace Xtensive.Orm.Rse.Transformation
 {
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriter.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriter.cs
index 851a86aa08..c9d209b399 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriter.cs
@@ -4,8 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.24
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriterState.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriterState.cs
index f9fb0b85cc..a9a09c4c80 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriterState.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/SkipTakeRewriterState.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.21
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Rse.Transformation
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/OrderingCorrector.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/OrderingCorrector.cs
index 0314b07a6c..3405d6d4dd 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/OrderingCorrector.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/OrderingCorrector.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.03.30
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Orm.Rse.Compilation;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/ProviderOrderingDescriptor.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/ProviderOrderingDescriptor.cs
index b15b96d4ee..c1fc020b72 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/ProviderOrderingDescriptor.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/ProviderOrderingDescriptor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.04.24
 
-using System;
 
 using Xtensive.Orm.Rse.Providers;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnOptimizer.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnOptimizer.cs
index 69667830e0..8039dba2b2 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnOptimizer.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnOptimizer.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.12
 
-using System;
 using Xtensive.Orm.Rse.Compilation;
 using Xtensive.Orm.Rse.Providers;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnRemover.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnRemover.cs
index fd96fd790f..34d5b7af9d 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnRemover.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/RedundantColumnRemover.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.10.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/SkipTakeCorrector.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/SkipTakeCorrector.cs
index 47ab3e89a3..55a2277f06 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/SkipTakeCorrector.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/SkipTakeCorrector.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.04.24
 
-using System;
 using Xtensive.Orm.Rse.Compilation;
 using Xtensive.Orm.Rse.Providers;
 
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessGatherer.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessGatherer.cs
index 7442886e85..ffe47a3132 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessGatherer.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessGatherer.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.17
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessRewriter.cs b/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessRewriter.cs
index d0b00e5652..b25d2fbc02 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessRewriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/Transformation/TupleAccessRewriter.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.17
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using ExpressionVisitor = Xtensive.Linq.ExpressionVisitor;
diff --git a/Orm/Xtensive.Orm/Orm/Rse/TupleExpressionExtensions.cs b/Orm/Xtensive.Orm/Orm/Rse/TupleExpressionExtensions.cs
index 8bae77d40b..dd31d2efff 100644
--- a/Orm/Xtensive.Orm/Orm/Rse/TupleExpressionExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Rse/TupleExpressionExtensions.cs
@@ -4,9 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2009.03.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Serialization/DeserializationContext.cs b/Orm/Xtensive.Orm/Orm/Serialization/DeserializationContext.cs
index 4175d724fe..c6bbf1c694 100644
--- a/Orm/Xtensive.Orm/Orm/Serialization/DeserializationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Serialization/DeserializationContext.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.03.30
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Orm/Serialization/EntityReference.cs b/Orm/Xtensive.Orm/Orm/Serialization/EntityReference.cs
index 7593b65ad1..deb7967c1c 100644
--- a/Orm/Xtensive.Orm/Orm/Serialization/EntityReference.cs
+++ b/Orm/Xtensive.Orm/Orm/Serialization/EntityReference.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.03.18
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Serialization/SerializationContext.cs b/Orm/Xtensive.Orm/Orm/Serialization/SerializationContext.cs
index d09b3818c2..386f31acff 100644
--- a/Orm/Xtensive.Orm/Orm/Serialization/SerializationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Serialization/SerializationContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.03.18
 
-using System;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Serialization/SerializationHelper.cs b/Orm/Xtensive.Orm/Orm/Serialization/SerializationHelper.cs
index ce46e97f67..10815bd660 100644
--- a/Orm/Xtensive.Orm/Orm/Serialization/SerializationHelper.cs
+++ b/Orm/Xtensive.Orm/Orm/Serialization/SerializationHelper.cs
@@ -4,15 +4,12 @@
 // Created by: Alex Kofman
 // Created:    2009.03.24
 
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using System.Security;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 using Xtensive.Tuples;
 using Tuple = Xtensive.Tuples.Tuple;
-using System.Linq;
 
 namespace Xtensive.Orm.Serialization
 {
diff --git a/Orm/Xtensive.Orm/Orm/Services/DirectEntityAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/DirectEntityAccessor.cs
index d863a2c4af..9d31ffce8d 100644
--- a/Orm/Xtensive.Orm/Orm/Services/DirectEntityAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/DirectEntityAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.02
 
-using System;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Services/DirectEntitySetAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/DirectEntitySetAccessor.cs
index 317ca24e28..941b53f1ea 100644
--- a/Orm/Xtensive.Orm/Orm/Services/DirectEntitySetAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/DirectEntitySetAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.06
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Orm/Services/DirectPersistentAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/DirectPersistentAccessor.cs
index 5aa8ab9471..b2186cb021 100644
--- a/Orm/Xtensive.Orm/Orm/Services/DirectPersistentAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/DirectPersistentAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.02
 
-using System;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Services/DirectSessionAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/DirectSessionAccessor.cs
index 0d5e115273..f85aaaa252 100644
--- a/Orm/Xtensive.Orm/Orm/Services/DirectSessionAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/DirectSessionAccessor.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2008.11.05
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Services/Old/EntitySetStateAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/Old/EntitySetStateAccessor.cs
index 667aa9063f..50de2f4c45 100644
--- a/Orm/Xtensive.Orm/Orm/Services/Old/EntitySetStateAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/Old/EntitySetStateAccessor.cs
@@ -5,9 +5,7 @@
 // Created:    2009.12.18
 
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Collections;
 
 namespace Xtensive.Orm.Services
diff --git a/Orm/Xtensive.Orm/Orm/Services/Old/PersistentStateAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/Old/PersistentStateAccessor.cs
index e8134a788d..523082193a 100644
--- a/Orm/Xtensive.Orm/Orm/Services/Old/PersistentStateAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/Old/PersistentStateAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.31
 
-using System;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Services
diff --git a/Orm/Xtensive.Orm/Orm/Services/Old/SessionStateAccessor.cs b/Orm/Xtensive.Orm/Orm/Services/Old/SessionStateAccessor.cs
index 6af7c6e410..c64b8f6af5 100644
--- a/Orm/Xtensive.Orm/Orm/Services/Old/SessionStateAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/Old/SessionStateAccessor.cs
@@ -4,11 +4,8 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.18
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Caching;
 
 namespace Xtensive.Orm.Services
diff --git a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryBuilder.cs b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryBuilder.cs
index 59b1811e69..83afb85c4b 100644
--- a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryBuilder.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.26
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryCommand.cs b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryCommand.cs
index 443876580a..d8fc6b22e1 100644
--- a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryCommand.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryCommand.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.27
 
-using System;
 using System.Data.Common;
 using System.Runtime.CompilerServices;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Providers;
 
 namespace Xtensive.Orm.Services
diff --git a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryParameterBinding.cs b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryParameterBinding.cs
index b70f74c9fd..bd739bc307 100644
--- a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryParameterBinding.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryParameterBinding.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.26
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryRequest.cs b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryRequest.cs
index 54d542db17..f088855532 100644
--- a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryRequest.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryRequest.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.26
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql.Compiler;
 
diff --git a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryTranslationResult.cs b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryTranslationResult.cs
index 891f318fa7..cb5f17a446 100644
--- a/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryTranslationResult.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/QueryBuilding/QueryTranslationResult.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.27
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Sql;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Orm/Services/QueryFormatter.cs b/Orm/Xtensive.Orm/Orm/Services/QueryFormatter.cs
index 2218ea6cc3..ffaa0ebce1 100644
--- a/Orm/Xtensive.Orm/Orm/Services/QueryFormatter.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/QueryFormatter.cs
@@ -4,9 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2011.03.02
 
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Services/TransactionMonitor.cs b/Orm/Xtensive.Orm/Orm/Services/TransactionMonitor.cs
index f440c246f1..ec1359dc09 100644
--- a/Orm/Xtensive.Orm/Orm/Services/TransactionMonitor.cs
+++ b/Orm/Xtensive.Orm/Orm/Services/TransactionMonitor.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.11.26
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 
 using Xtensive.IoC;
diff --git a/Orm/Xtensive.Orm/Orm/Session.Cache.cs b/Orm/Xtensive.Orm/Orm/Session.Cache.cs
index 4e51c60669..3086990000 100644
--- a/Orm/Xtensive.Orm/Orm/Session.Cache.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.Cache.cs
@@ -4,11 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.11.07
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Caching;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Session.Events.cs b/Orm/Xtensive.Orm/Orm/Session.Events.cs
index 08b0ed2f31..b3a3583355 100644
--- a/Orm/Xtensive.Orm/Orm/Session.Events.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.Events.cs
@@ -4,13 +4,11 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.06.29
 
-using System;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Transactions;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Operations;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Session.Persist.cs b/Orm/Xtensive.Orm/Orm/Session.Persist.cs
index a8990861f4..2eab13709e 100644
--- a/Orm/Xtensive.Orm/Orm/Session.Persist.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.Persist.cs
@@ -4,12 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.10
 
-using System;
 using System.Transactions;
-using System.Linq;
 using System.Runtime.InteropServices.ComTypes;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Session.Query.cs b/Orm/Xtensive.Orm/Orm/Session.Query.cs
index 438b3370c4..13397655a7 100644
--- a/Orm/Xtensive.Orm/Orm/Session.Query.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.Query.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.09.09
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Session.QueryTasks.cs b/Orm/Xtensive.Orm/Orm/Session.QueryTasks.cs
index ab51dbb902..121cabc062 100644
--- a/Orm/Xtensive.Orm/Orm/Session.QueryTasks.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.QueryTasks.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.10.09
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Orm.Internals;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Session.SystemLogic.cs b/Orm/Xtensive.Orm/Orm/Session.SystemLogic.cs
index a33e69beba..4bdd4f5d03 100644
--- a/Orm/Xtensive.Orm/Orm/Session.SystemLogic.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.SystemLogic.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.03
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Session.Transactions.cs b/Orm/Xtensive.Orm/Orm/Session.Transactions.cs
index a68c035d04..7079bc1551 100644
--- a/Orm/Xtensive.Orm/Orm/Session.Transactions.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.Transactions.cs
@@ -4,10 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.11.07
 
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Transactions;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Internals;
diff --git a/Orm/Xtensive.Orm/Orm/Session.Validation.cs b/Orm/Xtensive.Orm/Orm/Session.Validation.cs
index 0e6cf49708..f237850ac6 100644
--- a/Orm/Xtensive.Orm/Orm/Session.Validation.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.Validation.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.11.07
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Orm.Validation;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/Session.cs b/Orm/Xtensive.Orm/Orm/Session.cs
index df4f332675..1517108e89 100644
--- a/Orm/Xtensive.Orm/Orm/Session.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.cs
@@ -4,13 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.10
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Diagnostics;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/SessionBound.cs b/Orm/Xtensive.Orm/Orm/SessionBound.cs
index 87a3b29550..3ee6e65dbc 100644
--- a/Orm/Xtensive.Orm/Orm/SessionBound.cs
+++ b/Orm/Xtensive.Orm/Orm/SessionBound.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.10
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/SessionEventAccessor.cs b/Orm/Xtensive.Orm/Orm/SessionEventAccessor.cs
index 7dcc4ef380..6b4383fca0 100644
--- a/Orm/Xtensive.Orm/Orm/SessionEventAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/SessionEventAccessor.cs
@@ -4,11 +4,9 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.10
 
-using System;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Data.Common;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/SessionEventArgs.cs b/Orm/Xtensive.Orm/Orm/SessionEventArgs.cs
index 1e9bc355d8..89894fd764 100644
--- a/Orm/Xtensive.Orm/Orm/SessionEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/SessionEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.04
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/SessionScope.cs b/Orm/Xtensive.Orm/Orm/SessionScope.cs
index 43024817b4..c7a3333be2 100644
--- a/Orm/Xtensive.Orm/Orm/SessionScope.cs
+++ b/Orm/Xtensive.Orm/Orm/SessionScope.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.29
 
-using System;
-using System.Threading;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/StorageNode.cs b/Orm/Xtensive.Orm/Orm/StorageNode.cs
index 20ac4d09b1..d41ca26334 100644
--- a/Orm/Xtensive.Orm/Orm/StorageNode.cs
+++ b/Orm/Xtensive.Orm/Orm/StorageNode.cs
@@ -4,11 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Interfaces;
diff --git a/Orm/Xtensive.Orm/Orm/StorageNodeManager.cs b/Orm/Xtensive.Orm/Orm/StorageNodeManager.cs
index 8890797b5c..c00fe5693c 100644
--- a/Orm/Xtensive.Orm/Orm/StorageNodeManager.cs
+++ b/Orm/Xtensive.Orm/Orm/StorageNodeManager.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2014.03.13
 
-using System;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Structure.cs b/Orm/Xtensive.Orm/Orm/Structure.cs
index 9b9108409a..0dacf1544a 100644
--- a/Orm/Xtensive.Orm/Orm/Structure.cs
+++ b/Orm/Xtensive.Orm/Orm/Structure.cs
@@ -4,10 +4,8 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.01
 
-using System;
 using System.ComponentModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Runtime.Serialization;
 using Xtensive.Comparison;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/TargetKind.cs b/Orm/Xtensive.Orm/Orm/TargetKind.cs
index a14ad4d60f..e1860053e8 100644
--- a/Orm/Xtensive.Orm/Orm/TargetKind.cs
+++ b/Orm/Xtensive.Orm/Orm/TargetKind.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.09
 
-using System;
 
 namespace Xtensive.Orm {
 
diff --git a/Orm/Xtensive.Orm/Orm/Transaction.cs b/Orm/Xtensive.Orm/Orm/Transaction.cs
index 60490b54f7..0a527b9c4f 100644
--- a/Orm/Xtensive.Orm/Orm/Transaction.cs
+++ b/Orm/Xtensive.Orm/Orm/Transaction.cs
@@ -4,11 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.08.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using System.Transactions;
 using JetBrains.Annotations;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/TransactionEventArgs.cs b/Orm/Xtensive.Orm/Orm/TransactionEventArgs.cs
index d14ab74c9b..a03638f043 100644
--- a/Orm/Xtensive.Orm/Orm/TransactionEventArgs.cs
+++ b/Orm/Xtensive.Orm/Orm/TransactionEventArgs.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.06.04
 
-using System;
 
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/TransactionScope.cs b/Orm/Xtensive.Orm/Orm/TransactionScope.cs
index 732f10f054..eb783bb630 100644
--- a/Orm/Xtensive.Orm/Orm/TransactionScope.cs
+++ b/Orm/Xtensive.Orm/Orm/TransactionScope.cs
@@ -4,8 +4,6 @@
 // Created by: 
 // Created:    2008.08.30
 
-using System;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/TransactionState.cs b/Orm/Xtensive.Orm/Orm/TransactionState.cs
index d29eea03e7..7e9158166b 100644
--- a/Orm/Xtensive.Orm/Orm/TransactionState.cs
+++ b/Orm/Xtensive.Orm/Orm/TransactionState.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2007.11.02
 
-using System;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/TransactionalExtensions.cs b/Orm/Xtensive.Orm/Orm/TransactionalExtensions.cs
index 2fc87f6efa..aaebd63e06 100644
--- a/Orm/Xtensive.Orm/Orm/TransactionalExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/TransactionalExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.07.31
 
-using System;
-using System.Collections.Generic;
 using System.Transactions;
 
 namespace Xtensive.Orm
diff --git a/Orm/Xtensive.Orm/Orm/TransactionalValue.cs b/Orm/Xtensive.Orm/Orm/TransactionalValue.cs
index aae98a3f40..8713ed5a89 100644
--- a/Orm/Xtensive.Orm/Orm/TransactionalValue.cs
+++ b/Orm/Xtensive.Orm/Orm/TransactionalValue.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.12.18
 
-using System;
 using Xtensive.Caching;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/TypeReference.cs b/Orm/Xtensive.Orm/Orm/TypeReference.cs
index 93faa6d0f9..a818a7bd32 100644
--- a/Orm/Xtensive.Orm/Orm/TypeReference.cs
+++ b/Orm/Xtensive.Orm/Orm/TypeReference.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.10.09
 
-using System;
 
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/AssemblyInfoAttribute.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/AssemblyInfoAttribute.cs
index fc357f60bf..130a8bacd7 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/AssemblyInfoAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/AssemblyInfoAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.30
 
-using System;
 
 
 namespace Xtensive.Orm.Upgrade
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/RecycledAttribute.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/RecycledAttribute.cs
index 38906a90ef..e9e0921c58 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/RecycledAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Attributes/RecycledAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.30
 
-using System;
 
 
 namespace Xtensive.Orm.Upgrade
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/DomainUpgradeModeExtensions.cs b/Orm/Xtensive.Orm/Orm/Upgrade/DomainUpgradeModeExtensions.cs
index 2c5b3ac165..7d5f6642a8 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/DomainUpgradeModeExtensions.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/DomainUpgradeModeExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.03.05
 
-using System;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/ChangeFieldTypeHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/ChangeFieldTypeHint.cs
index d13c307ff2..d0071a1db1 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/ChangeFieldTypeHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/ChangeFieldTypeHint.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.05
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/CopyFieldHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/CopyFieldHint.cs
index c05ac1f500..9555c98dfb 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/CopyFieldHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/CopyFieldHint.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Kryuchkov
 // Created:    2009.05.29
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MergeTypeHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MergeTypeHint.cs
index 6760711096..d190854908 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MergeTypeHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MergeTypeHint.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.29
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MoveFieldHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MoveFieldHint.cs
index 22fb78d3f0..0094b75373 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MoveFieldHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/MoveFieldHint.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.14
 
-using System;
 using System.Diagnostics;
 using System.Linq.Expressions;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RecycledTypeHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RecycledTypeHint.cs
index 7152490faf..23811140f0 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RecycledTypeHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RecycledTypeHint.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.29
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveFieldHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveFieldHint.cs
index 90413bb2c4..4034b6f50b 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveFieldHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveFieldHint.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveTypeHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveTypeHint.cs
index a922dadcee..c78ec7158d 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveTypeHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RemoveTypeHint.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.09
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameFieldHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameFieldHint.cs
index 76a75def7d..c666dec2d2 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameFieldHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameFieldHint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.29
 
-using System;
 using System.Linq.Expressions;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameTypeHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameTypeHint.cs
index a8288190a0..2f3f458fb0 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameTypeHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/RenameTypeHint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.29
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/UpgradeHint.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/UpgradeHint.cs
index 5b94bfe73f..011c0d7b69 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Hints/UpgradeHint.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Hints/UpgradeHint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.29
 
-using System;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Interfaces/IUpgradeHandler.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Interfaces/IUpgradeHandler.cs
index c77d7885f4..01c78edd13 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Interfaces/IUpgradeHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Interfaces/IUpgradeHandler.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Kofman
 // Created:    2009.04.08
 
-using System;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/CatalogCloner.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/CatalogCloner.cs
index d59ef708b4..cb1a22e0f7 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/CatalogCloner.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/CatalogCloner.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.10.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainExtractedModelBuilder.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainExtractedModelBuilder.cs
index 542eba21cd..6f8e270fdd 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainExtractedModelBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainExtractedModelBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.23
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainModelConverter.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainModelConverter.cs
index da8257834c..0b4437c2fc 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainModelConverter.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/DomainModelConverter.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.02
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerationResult.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerationResult.cs
index 9b819a93be..99e9b92c3f 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerationResult.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerationResult.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.10.14
 
-using System.Collections.Generic;
 using Xtensive.Modelling.Comparison.Hints;
 
 namespace Xtensive.Orm.Upgrade
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerator.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerator.cs
index b13e86b858..286af757cc 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerator.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/HintGenerator.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.04
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Modelling.Comparison.Hints;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/IgnoreRulesHandler.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/IgnoreRulesHandler.cs
index 3c86bce2de..40a974459e 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/IgnoreRulesHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/IgnoreRulesHandler.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Interfaces/IUpgradeHintsProcessor.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Interfaces/IUpgradeHintsProcessor.cs
index f97c0acd9f..98edaa78a1 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Interfaces/IUpgradeHintsProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Interfaces/IUpgradeHintsProcessor.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.01.22
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Upgrade.Internals.Interfaces
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataExtractor.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataExtractor.cs
index 90dc5eed28..2117f72098 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataExtractor.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataExtractor.cs
@@ -4,13 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.02.16
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataMapping.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataMapping.cs
index 724aeb79d4..890518eca0 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataMapping.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataMapping.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
-using System;
-using System.Linq;
 using System.Linq.Expressions;
 using Xtensive.Core;
 using Xtensive.Orm.Metadata;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataSet.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataSet.cs
index 3b859cd7b2..32dcc29da1 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataSet.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataSet.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataWriter.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataWriter.cs
index 0dd9e741d7..6d9a4bff89 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataWriter.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataWriter.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Providers;
 using Xtensive.Reflection;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NodeExtractedModelBuilder.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NodeExtractedModelBuilder.cs
index 2096b8da41..711766878a 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NodeExtractedModelBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NodeExtractedModelBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2016.02.23
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Configuration;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NullUpgradeHintsProcessor.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NullUpgradeHintsProcessor.cs
index 5ec0f40bd2..efc226f086 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NullUpgradeHintsProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/NullUpgradeHintsProcessor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.01.22
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model.Stored;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/PartialIndexInfoMap.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/PartialIndexInfoMap.cs
index d492088599..1c24fdd73f 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/PartialIndexInfoMap.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/PartialIndexInfoMap.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.07.18
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Model.Stored;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/RuleMatcher.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/RuleMatcher.cs
index 3b8a647e15..f15201038c 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/RuleMatcher.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/RuleMatcher.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.08.20
 
-using System.Collections.Generic;
-using System.Linq;
 using System.Text.RegularExpressions;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaComparer.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaComparer.cs
index d992ef9fb8..bccf7856a2 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaComparer.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaComparer.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaExtractor.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaExtractor.cs
index ed3185b358..8017b75a22 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaExtractor.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaExtractor.cs
@@ -4,10 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.16
 
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Model.Stored;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaUpgrader.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaUpgrader.cs
index 62a74ba4df..af11a5ac82 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaUpgrader.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SchemaUpgrader.cs
@@ -4,11 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.06
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Logging;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlActionTranslator.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlActionTranslator.cs
index 0ab2ee6936..62e684c043 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlActionTranslator.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlActionTranslator.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.24
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlAsyncWorker.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlAsyncWorker.cs
index e8e22933b0..5542ef1032 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlAsyncWorker.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlAsyncWorker.cs
@@ -2,11 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlModelConverter.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlModelConverter.cs
index d1858fdfa4..7acd843bde 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlModelConverter.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlModelConverter.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.31
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Model.Stored;
 using Xtensive.Orm.Providers;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorker.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorker.cs
index a9b063fd03..83f2a4eecb 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorker.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorker.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.15
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorkerTask.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorkerTask.cs
index 6212a2ec77..023c9dfbe0 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorkerTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/SqlWorkerTask.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.15
 
-using System;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/StageModelFilter.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/StageModelFilter.cs
index 56e061850c..cba0b3f7a5 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/StageModelFilter.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/StageModelFilter.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.14
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/TypeIdProvider.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/TypeIdProvider.cs
index 773b2fba52..d333810669 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/TypeIdProvider.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/TypeIdProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.19
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeActionSequenceBuilder.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeActionSequenceBuilder.cs
index 06137103d2..70e37f5dc5 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeActionSequenceBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeActionSequenceBuilder.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.18
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm.Providers;
 using Xtensive.Sql;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintValidator.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintValidator.cs
index fbab6d261b..ef693f66d2 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintValidator.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.01.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model.Stored;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessingResult.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessingResult.cs
index 4727ba40a0..24e65d7de0 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessingResult.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessingResult.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.01.22
 
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model.Stored;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessor.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessor.cs
index e90f7eaf49..56f1339dd1 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeHintsProcessor.cs
@@ -4,9 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2015.01.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeServiceAccessor.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeServiceAccessor.cs
index 5eb3ae1000..0aac0f6afc 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeServiceAccessor.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/UpgradeServiceAccessor.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.03.14
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/WellKnownUpgradeTypes.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/WellKnownUpgradeTypes.cs
index da7e2e84a9..d4a735bb9e 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Internals/WellKnownUpgradeTypes.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Internals/WellKnownUpgradeTypes.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Orm.Upgrade.Model;
 
 namespace Xtensive.Orm.Upgrade
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoCollection.cs
index a90e584408..6d0a265039 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoRef.cs
index 7d92afd470..482cd11fd0 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ColumnInfoRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 
 namespace Xtensive.Orm.Upgrade.Model
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/IntegrityException.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/IntegrityException.cs
index cd6e13b65f..99dca8a31e 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/IntegrityException.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/IntegrityException.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 using System.Runtime.Serialization;
 
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/ValidationException.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/ValidationException.cs
index 5d6acd52c2..ea68a636e4 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/ValidationException.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/Exceptions/ValidationException.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 using System.Runtime.Serialization;
 using System.Security;
 using System.Security.Permissions;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyCollection.cs
index 20796c6d5f..7b814092ad 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
 
 using Xtensive.Modelling;
 using Xtensive.Orm.Upgrade.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnCollection.cs
index d94d254bc4..a302712f4f 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Upgrade.Model
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnRef.cs
index 001d991aed..c8903a2639 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.20
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyInfo.cs
index 5f87f5bb2c..e3edfac907 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ForeignKeyInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.23
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRef.cs
index 1de0251bbe..089d4d0983 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.14
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRefCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRefCollection.cs
index e080c8a678..00ba6d4823 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.14
 
-using System;
 using System.Diagnostics;
 
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextIndexInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextIndexInfoCollection.cs
index cba4efdfad..fb96e7aaed 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextIndexInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/FullTextIndexInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.25
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRef.cs
index 18519d6f50..8b57973bea 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRefCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRefCollection.cs
index b86e941555..d548904ded 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/IncludedColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef.cs
index 446bfe634c..b9a35272ac 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRefCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRefCollection.cs
index 30473adec2..55b6279900 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 
 namespace Xtensive.Orm.Upgrade.Model
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef{TParent}.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef{TParent}.cs
index 33afbc2e03..a891afa417 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef{TParent}.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/KeyColumnRef{TParent}.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling.Attributes;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeBase.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeBase.cs
index e4beaa8257..51147a17a5 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeBase.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeBase.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeCollectionBase.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeCollectionBase.cs
index eb466fd687..f90f369cd7 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeCollectionBase.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/NodeCollectionBase.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Modelling;
 
 namespace Xtensive.Orm.Upgrade.Model
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PartialIndexFilterInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PartialIndexFilterInfo.cs
index 13e68ff93e..f042703c76 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PartialIndexFilterInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PartialIndexFilterInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2011.10.13
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Upgrade.Model
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryIndexInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryIndexInfo.cs
index b9b01a6272..f6e0606fc1 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryIndexInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryIndexInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRef.cs
index 3ac334747d..9f7f492763 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRefCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRefCollection.cs
index 6bf5e37836..69a4e6797c 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/PrimaryKeyColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 
 namespace Xtensive.Orm.Upgrade.Model
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/Ref.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/Ref.cs
index 5eb2cdf75e..af84f53b42 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/Ref.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/Ref.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ReferentialAction.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ReferentialAction.cs
index 8b49c7b821..1f855eea44 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ReferentialAction.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ReferentialAction.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.17
 
-using System;
 
 namespace Xtensive.Orm.Upgrade.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfo.cs
index 81887eef1a..573867a14e 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfoCollection.cs
index 853661a483..46209c6ba1 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/SecondaryIndexInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/SequenceInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/SequenceInfoCollection.cs
index 33145e64ff..34b0ddaaa9 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/SequenceInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/SequenceInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.29
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageColumnInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageColumnInfo.cs
index f87a2bae98..3fb5ed59bf 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageColumnInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageColumnInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageFullTextIndexInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageFullTextIndexInfo.cs
index c2b19636fb..0f905e7345 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageFullTextIndexInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageFullTextIndexInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.01.14
 
-using System;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Modelling;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageIndexInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageIndexInfo.cs
index 75bedeaff7..acee34ec02 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageIndexInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageIndexInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Core;
 
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageModel.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageModel.cs
index 88cf149090..a9d148f6db 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageModel.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageModel.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.20
 
-using System;
 
 using Xtensive.Modelling;
 using Xtensive.Modelling.Actions;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageSequenceInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageSequenceInfo.cs
index c7a5d059fd..0076588230 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageSequenceInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageSequenceInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.04.29
 
-using System;
 using Xtensive.Core;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageTypeInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageTypeInfo.cs
index ea3c319e17..faa5b18215 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageTypeInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/StorageTypeInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using System.Globalization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfo.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfo.cs
index 07beb0e689..387751040c 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfo.cs
@@ -4,10 +4,8 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 using Xtensive.Modelling;
 using Xtensive.Modelling.Attributes;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Upgrade.Model
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfoCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfoCollection.cs
index dde50c7d98..5d322e23ad 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfoCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/TableInfoCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRef.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRef.cs
index 639ece5bd4..4f0707c6d7 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRef.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRef.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRefCollection.cs b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRefCollection.cs
index 12199ac4b5..7b93751224 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRefCollection.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/Model/ValueColumnRefCollection.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.24
 
-using System;
 
 using Xtensive.Modelling;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/SchemaComparisonResult.cs b/Orm/Xtensive.Orm/Orm/Upgrade/SchemaComparisonResult.cs
index 819e94ea0f..f01ef46de2 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/SchemaComparisonResult.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/SchemaComparisonResult.cs
@@ -4,10 +4,7 @@
 // Created by: Ivan Galkin
 // Created:    2009.05.01
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Modelling.Actions;
 using Xtensive.Modelling.Comparison;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/SchemaExtractionResult.cs b/Orm/Xtensive.Orm/Orm/Upgrade/SchemaExtractionResult.cs
index 93f7e6c493..6a0e9c5f33 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/SchemaExtractionResult.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/SchemaExtractionResult.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kulakov
 // Created:    2013.09.02
 
-using System.Collections.Generic;
 using Xtensive.Sql;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/SystemUpgradeHandler.cs b/Orm/Xtensive.Orm/Orm/Upgrade/SystemUpgradeHandler.cs
index fa3a0498e9..21f9d6056e 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/SystemUpgradeHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/SystemUpgradeHandler.cs
@@ -4,12 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2009.05.01
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm.Building.Builders;
 using Xtensive.Orm.Configuration;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/TypeConversionVerifier.cs b/Orm/Xtensive.Orm/Orm/Upgrade/TypeConversionVerifier.cs
index 9341982e22..919c0333b6 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/TypeConversionVerifier.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/TypeConversionVerifier.cs
@@ -4,8 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.05.28
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Orm.Upgrade.Model;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeActionSequence.cs b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeActionSequence.cs
index f9a5967487..42ee99edf6 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeActionSequence.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeActionSequence.cs
@@ -4,12 +4,7 @@
 // Created by: Dmitri Maximov
 // Created:    2011.07.15
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Upgrade
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeContext.cs b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeContext.cs
index fb01486de1..b72f12e886 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeContext.cs
@@ -4,8 +4,6 @@
 // Created by: Aleksey Gamzov
 // Created:    2008.12.30
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
 using System.Reflection;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeHandler.cs b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeHandler.cs
index 6f3c0a89ba..4deff741e2 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeHandler.cs
@@ -4,14 +4,9 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.30
 
-using System;
-using System.Collections.Generic;
 using System.Reflection;
 using Xtensive.Core;
 using Xtensive.Reflection;
-using System.Linq;
-using System.Threading.Tasks;
-using System.Threading;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeStage.cs b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeStage.cs
index 9ffc0383c3..83e64a7fb2 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeStage.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradeStage.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2009.04.30
 
-using System;
 
 namespace Xtensive.Orm.Upgrade
 {
diff --git a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradingDomainBuilder.cs b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradingDomainBuilder.cs
index 3abe3670f5..6dd29f4d14 100644
--- a/Orm/Xtensive.Orm/Orm/Upgrade/UpgradingDomainBuilder.cs
+++ b/Orm/Xtensive.Orm/Orm/Upgrade/UpgradingDomainBuilder.cs
@@ -4,13 +4,8 @@
 // Created by: Alex Kofman
 // Created:    2009.04.23
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using System.Reflection;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.IoC;
 using Xtensive.Modelling.Comparison;
diff --git a/Orm/Xtensive.Orm/Orm/UrlInfo.cs b/Orm/Xtensive.Orm/Orm/UrlInfo.cs
index 82f49b11fa..8d961ada16 100644
--- a/Orm/Xtensive.Orm/Orm/UrlInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/UrlInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2007.06.08
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.ComponentModel;
 using System.Diagnostics;
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/EmailConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/EmailConstraint.cs
index 75905eb4a8..b4cbad22b4 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/EmailConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/EmailConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.05.27
 
-using System;
 using System.Text.RegularExpressions;
 using Xtensive.Orm.Model;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/FutureConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/FutureConstraint.cs
index cbabb2b0f5..074d77f63d 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/FutureConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/FutureConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.05.27
 
-using System;
 using Xtensive.Orm.Model;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotEmptyConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotEmptyConstraint.cs
index d1fe8945de..59bd7f609e 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotEmptyConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotEmptyConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.05.27
 
-using System;
 using Xtensive.Orm.Model;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullConstraint.cs
index edd2be36f0..253d81d4c9 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.05.27
 
-using System;
 
 namespace Xtensive.Orm.Validation
 {
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullOrEmptyConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullOrEmptyConstraint.cs
index 40f28c7ae8..cd29c8638f 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullOrEmptyConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/NotNullOrEmptyConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.05.27
 
-using System;
 using Xtensive.Orm.Model;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/PastConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/PastConstraint.cs
index 48b04691fc..2dfc7609b1 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/PastConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/PastConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.05.27
 
-using System;
 using Xtensive.Reflection;
 
 namespace Xtensive.Orm.Validation
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/RangeConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/RangeConstraint.cs
index 51d643d4c4..b7e1ce2775 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/RangeConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/RangeConstraint.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.07.25
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Comparison;
 using Xtensive.Orm.Model;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Constraints/RegexConstraint.cs b/Orm/Xtensive.Orm/Orm/Validation/Constraints/RegexConstraint.cs
index 0ce05f7a50..3382a8405d 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Constraints/RegexConstraint.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Constraints/RegexConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2008.07.23
 
-using System;
 using System.Text.RegularExpressions;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/EntityErrorInfo.cs b/Orm/Xtensive.Orm/Orm/Validation/EntityErrorInfo.cs
index ac5f87c9f4..dad23f5168 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/EntityErrorInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/EntityErrorInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.09
 
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Orm.Validation
diff --git a/Orm/Xtensive.Orm/Orm/Validation/EntitySetFieldValidator.cs b/Orm/Xtensive.Orm/Orm/Validation/EntitySetFieldValidator.cs
index f6885e0ae7..fb220c008c 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/EntitySetFieldValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/EntitySetFieldValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.11
 
-using System;
 
 namespace Xtensive.Orm.Validation
 {
diff --git a/Orm/Xtensive.Orm/Orm/Validation/EntityValidator.cs b/Orm/Xtensive.Orm/Orm/Validation/EntityValidator.cs
index d2752c3742..f82e356f3f 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/EntityValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/EntityValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.11
 
-using System;
 
 namespace Xtensive.Orm.Validation
 {
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Exceptions/ValidationFailedException.cs b/Orm/Xtensive.Orm/Orm/Validation/Exceptions/ValidationFailedException.cs
index 929acc3d74..12664c85c2 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Exceptions/ValidationFailedException.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Exceptions/ValidationFailedException.cs
@@ -1,5 +1,3 @@
-using System;
-using System.Collections.Generic;
 using System.Runtime.Serialization;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Internals/RealValidationContext.cs b/Orm/Xtensive.Orm/Orm/Validation/Internals/RealValidationContext.cs
index 0caef363f6..761a178772 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Internals/RealValidationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Internals/RealValidationContext.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.12
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Validation
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Internals/ValidationContext.cs b/Orm/Xtensive.Orm/Orm/Validation/Internals/ValidationContext.cs
index 2ac95236fc..2935255428 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Internals/ValidationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Internals/ValidationContext.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.05
 
-using System.Collections.Generic;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Validation
diff --git a/Orm/Xtensive.Orm/Orm/Validation/Internals/VoidValidationContext.cs b/Orm/Xtensive.Orm/Orm/Validation/Internals/VoidValidationContext.cs
index 99a525a8ec..4b338babde 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/Internals/VoidValidationContext.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/Internals/VoidValidationContext.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.12
 
-using System.Collections.Generic;
 using Xtensive.Orm.Model;
 
 namespace Xtensive.Orm.Validation
diff --git a/Orm/Xtensive.Orm/Orm/Validation/ObjectValidator.cs b/Orm/Xtensive.Orm/Orm/Validation/ObjectValidator.cs
index da3d3798f0..13eb06c8ea 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/ObjectValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/ObjectValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.06
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/PropertyValidator.cs b/Orm/Xtensive.Orm/Orm/Validation/PropertyValidator.cs
index 05f4e3c3d6..ca18f7aa7f 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/PropertyValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/PropertyValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.06
 
-using System;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
 
diff --git a/Orm/Xtensive.Orm/Orm/Validation/StructureFieldValidator.cs b/Orm/Xtensive.Orm/Orm/Validation/StructureFieldValidator.cs
index 5c3880a6c2..40a97c07ce 100644
--- a/Orm/Xtensive.Orm/Orm/Validation/StructureFieldValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/Validation/StructureFieldValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.11
 
-using System;
 
 namespace Xtensive.Orm.Validation
 {
diff --git a/Orm/Xtensive.Orm/Orm/VersionCapturer.cs b/Orm/Xtensive.Orm/Orm/VersionCapturer.cs
index 1d96ac0da6..70c7074460 100644
--- a/Orm/Xtensive.Orm/Orm/VersionCapturer.cs
+++ b/Orm/Xtensive.Orm/Orm/VersionCapturer.cs
@@ -4,12 +4,9 @@
 // Created by: Alex Yakunin
 // Created:    2010.03.01
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 using Xtensive.Tuples.Transform;
-using System.Linq;
 
 namespace Xtensive.Orm
 {
diff --git a/Orm/Xtensive.Orm/Orm/VersionInfo.cs b/Orm/Xtensive.Orm/Orm/VersionInfo.cs
index ff38fcc6c9..cfda8cce77 100644
--- a/Orm/Xtensive.Orm/Orm/VersionInfo.cs
+++ b/Orm/Xtensive.Orm/Orm/VersionInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.08.13
 
-using System;
 using System.Collections;
 using System.Diagnostics;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Orm/VersionSet.cs b/Orm/Xtensive.Orm/Orm/VersionSet.cs
index 09cf4ee345..3e1a223895 100644
--- a/Orm/Xtensive.Orm/Orm/VersionSet.cs
+++ b/Orm/Xtensive.Orm/Orm/VersionSet.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2010.03.01
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Logging;
 
diff --git a/Orm/Xtensive.Orm/Orm/VersionValidator.cs b/Orm/Xtensive.Orm/Orm/VersionValidator.cs
index 93955fc904..0bbf061426 100644
--- a/Orm/Xtensive.Orm/Orm/VersionValidator.cs
+++ b/Orm/Xtensive.Orm/Orm/VersionValidator.cs
@@ -4,9 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.11.10
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Logging;
 
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/EntityInterfaceAttribute.cs b/Orm/Xtensive.Orm/Orm/Weaving/EntityInterfaceAttribute.cs
index 9a4d317a08..890d00e2eb 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/EntityInterfaceAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/EntityInterfaceAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.26
 
-using System;
 using JetBrains.Annotations;
 
 namespace Xtensive.Orm.Weaving
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/EntitySetTypeAttribute.cs b/Orm/Xtensive.Orm/Orm/Weaving/EntitySetTypeAttribute.cs
index 5b51376aa1..1d35cf5eb0 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/EntitySetTypeAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/EntitySetTypeAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.22
 
-using System;
 using JetBrains.Annotations;
 
 namespace Xtensive.Orm.Weaving
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/EntityTypeAttribute.cs b/Orm/Xtensive.Orm/Orm/Weaving/EntityTypeAttribute.cs
index 6e61dee0b4..a5200a724d 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/EntityTypeAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/EntityTypeAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 using JetBrains.Annotations;
 
 namespace Xtensive.Orm.Weaving
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/OverrideFieldNameAttribute.cs b/Orm/Xtensive.Orm/Orm/Weaving/OverrideFieldNameAttribute.cs
index a7234faae8..539aa906f7 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/OverrideFieldNameAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/OverrideFieldNameAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2010.07.13
 
-using System;
 
 namespace Xtensive.Orm.Weaving
 {
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/PersistenceImplementation.cs b/Orm/Xtensive.Orm/Orm/Weaving/PersistenceImplementation.cs
index 0d1b2462a0..d51688369e 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/PersistenceImplementation.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/PersistenceImplementation.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.27
 
-using System;
 
 namespace Xtensive.Orm.Weaving
 {
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/ProcessedByWeaverAttribute.cs b/Orm/Xtensive.Orm/Orm/Weaving/ProcessedByWeaverAttribute.cs
index 8d9ff89f59..afe56f1a26 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/ProcessedByWeaverAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/ProcessedByWeaverAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 using JetBrains.Annotations;
 
 namespace Xtensive.Orm.Weaving
diff --git a/Orm/Xtensive.Orm/Orm/Weaving/StructureTypeAttribute.cs b/Orm/Xtensive.Orm/Orm/Weaving/StructureTypeAttribute.cs
index 1ed187cd44..47f3edaa11 100644
--- a/Orm/Xtensive.Orm/Orm/Weaving/StructureTypeAttribute.cs
+++ b/Orm/Xtensive.Orm/Orm/Weaving/StructureTypeAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 using JetBrains.Annotations;
 
 namespace Xtensive.Orm.Weaving
diff --git a/Orm/Xtensive.Orm/Orm/WellKnown.cs b/Orm/Xtensive.Orm/Orm/WellKnown.cs
index f4c58a57cb..d5d678a545 100644
--- a/Orm/Xtensive.Orm/Orm/WellKnown.cs
+++ b/Orm/Xtensive.Orm/Orm/WellKnown.cs
@@ -4,9 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.21
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Orm.Internals;
 using Xtensive.Orm.Metadata;
diff --git a/Orm/Xtensive.Orm/Reflection/AttributeHelper.cs b/Orm/Xtensive.Orm/Reflection/AttributeHelper.cs
index f7b29466f4..7fa059b91b 100644
--- a/Orm/Xtensive.Orm/Reflection/AttributeHelper.cs
+++ b/Orm/Xtensive.Orm/Reflection/AttributeHelper.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.13
 
-using System;
-using System.Collections.Generic;
 using System.Collections.Concurrent;
-using System.Linq;
 using System.Reflection;
 using Xtensive.Core;
 using PerAttributeKey = System.ValueTuple<System.Reflection.MemberInfo, Xtensive.Reflection.AttributeSearchOptions>;
diff --git a/Orm/Xtensive.Orm/Reflection/AttributeSearchOptions.cs b/Orm/Xtensive.Orm/Reflection/AttributeSearchOptions.cs
index 21fadea929..3f868440c7 100644
--- a/Orm/Xtensive.Orm/Reflection/AttributeSearchOptions.cs
+++ b/Orm/Xtensive.Orm/Reflection/AttributeSearchOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.06
 
-using System;
 
 namespace Xtensive.Reflection
 {
diff --git a/Orm/Xtensive.Orm/Reflection/DelegateHelper.cs b/Orm/Xtensive.Orm/Reflection/DelegateHelper.cs
index 88fe84a71c..3d3c7ba477 100644
--- a/Orm/Xtensive.Orm/Reflection/DelegateHelper.cs
+++ b/Orm/Xtensive.Orm/Reflection/DelegateHelper.cs
@@ -4,10 +4,7 @@
 // Created by:
 // Created:    2007.10.25
 
-using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reflection;
 using System.Reflection.Emit;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Reflection/InterfaceMapping.cs b/Orm/Xtensive.Orm/Reflection/InterfaceMapping.cs
index cf161f4969..3bb3d3b941 100644
--- a/Orm/Xtensive.Orm/Reflection/InterfaceMapping.cs
+++ b/Orm/Xtensive.Orm/Reflection/InterfaceMapping.cs
@@ -4,12 +4,9 @@
 // Created by: Alex Yakunin
 // Created:    2010.08.30
 
-using System;
 using System.Reflection;
 
 using ReflectionInterfaceMapping=System.Reflection.InterfaceMapping;
-using System.Linq;
-using System.Collections.Generic;
 
 namespace Xtensive.Reflection
 {
diff --git a/Orm/Xtensive.Orm/Reflection/MemberHelper.cs b/Orm/Xtensive.Orm/Reflection/MemberHelper.cs
index 712409f5da..823f2ebbde 100644
--- a/Orm/Xtensive.Orm/Reflection/MemberHelper.cs
+++ b/Orm/Xtensive.Orm/Reflection/MemberHelper.cs
@@ -4,12 +4,10 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.13
 
-using System;
 using System.Reflection;
 using System.Security;
 using System.Text;
 using Xtensive.Reflection;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Reflection/MethodHelper.cs b/Orm/Xtensive.Orm/Reflection/MethodHelper.cs
index aa9f859eaf..025b63deee 100644
--- a/Orm/Xtensive.Orm/Reflection/MethodHelper.cs
+++ b/Orm/Xtensive.Orm/Reflection/MethodHelper.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.27
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using System.Reflection;
 using JetBrains.Annotations;
 using Xtensive.Collections;
diff --git a/Orm/Xtensive.Orm/Reflection/SequenceHelper.cs b/Orm/Xtensive.Orm/Reflection/SequenceHelper.cs
index 138989800f..4f21acac80 100644
--- a/Orm/Xtensive.Orm/Reflection/SequenceHelper.cs
+++ b/Orm/Xtensive.Orm/Reflection/SequenceHelper.cs
@@ -4,8 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.04.17
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Reflection
 {
diff --git a/Orm/Xtensive.Orm/Reflection/TypeHelper.cs b/Orm/Xtensive.Orm/Reflection/TypeHelper.cs
index ded198e5c9..f23ad0174f 100644
--- a/Orm/Xtensive.Orm/Reflection/TypeHelper.cs
+++ b/Orm/Xtensive.Orm/Reflection/TypeHelper.cs
@@ -4,18 +4,14 @@
 // Created by: Nick Svetlov
 // Created:    2007.06.13
 
-using System;
 using System.Collections;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
 using System.Reflection.Emit;
 using System.Runtime.CompilerServices;
 using System.Text;
-using System.Threading;
 using Xtensive.Collections;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Sorting;
diff --git a/Orm/Xtensive.Orm/Reflection/WellKnown.Queryable.cs b/Orm/Xtensive.Orm/Reflection/WellKnown.Queryable.cs
index bce5b2cee7..aae155d9a7 100644
--- a/Orm/Xtensive.Orm/Reflection/WellKnown.Queryable.cs
+++ b/Orm/Xtensive.Orm/Reflection/WellKnown.Queryable.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.24
 
-using System.Linq;
 
 namespace Xtensive.Reflection
 {
diff --git a/Orm/Xtensive.Orm/Reflection/WellKnown.cs b/Orm/Xtensive.Orm/Reflection/WellKnown.cs
index 5934a2ff24..2aedc4199e 100644
--- a/Orm/Xtensive.Orm/Reflection/WellKnown.cs
+++ b/Orm/Xtensive.Orm/Reflection/WellKnown.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.07.30
 
-using System.Linq;
 
 namespace Xtensive.Reflection
 {
diff --git a/Orm/Xtensive.Orm/Reflection/WellKnownInterfaces.cs b/Orm/Xtensive.Orm/Reflection/WellKnownInterfaces.cs
index 8f55696a3a..1a41ee35a0 100644
--- a/Orm/Xtensive.Orm/Reflection/WellKnownInterfaces.cs
+++ b/Orm/Xtensive.Orm/Reflection/WellKnownInterfaces.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 
 namespace Xtensive.Reflection
 {
diff --git a/Orm/Xtensive.Orm/Reflection/WellKnownTypes.cs b/Orm/Xtensive.Orm/Reflection/WellKnownTypes.cs
index 8a2c1244f7..c8c3c53f4b 100644
--- a/Orm/Xtensive.Orm/Reflection/WellKnownTypes.cs
+++ b/Orm/Xtensive.Orm/Reflection/WellKnownTypes.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using Xtensive.Orm.Linq;
diff --git a/Orm/Xtensive.Orm/Sorting/ConnectionType.cs b/Orm/Xtensive.Orm/Sorting/ConnectionType.cs
index 9eb8912c40..c701678a48 100644
--- a/Orm/Xtensive.Orm/Sorting/ConnectionType.cs
+++ b/Orm/Xtensive.Orm/Sorting/ConnectionType.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.10
 
-using System;
 
 namespace Xtensive.Sorting
 {
diff --git a/Orm/Xtensive.Orm/Sorting/Node.cs b/Orm/Xtensive.Orm/Sorting/Node.cs
index e07541db0d..1a588b1741 100644
--- a/Orm/Xtensive.Orm/Sorting/Node.cs
+++ b/Orm/Xtensive.Orm/Sorting/Node.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.13
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Sorting/NodeConnection.cs b/Orm/Xtensive.Orm/Sorting/NodeConnection.cs
index a877b65e83..f9fae50641 100644
--- a/Orm/Xtensive.Orm/Sorting/NodeConnection.cs
+++ b/Orm/Xtensive.Orm/Sorting/NodeConnection.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.03.13
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem, TConnectionItem}.cs b/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem, TConnectionItem}.cs
index 845fbbe7f6..f15d38fe81 100644
--- a/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem, TConnectionItem}.cs	
+++ b/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem, TConnectionItem}.cs	
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.10
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem}.cs b/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem}.cs
index b63a181d28..3aede6c374 100644
--- a/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem}.cs
+++ b/Orm/Xtensive.Orm/Sorting/TopologicalSortResult{TNodeItem}.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2009.12.10
 
-using System;
-using System.Collections.Generic;
 
 
 namespace Xtensive.Sorting
diff --git a/Orm/Xtensive.Orm/Sorting/TopologicalSorter.cs b/Orm/Xtensive.Orm/Sorting/TopologicalSorter.cs
index 282ee03543..6b53225ae8 100644
--- a/Orm/Xtensive.Orm/Sorting/TopologicalSorter.cs
+++ b/Orm/Xtensive.Orm/Sorting/TopologicalSorter.cs
@@ -4,10 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.08.07
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
-using System.Linq;
 using Xtensive.Core;
 using DotNetNotNullAttribute = System.Diagnostics.CodeAnalysis.NotNullAttribute;
 using JBNotNullAttribute = JetBrains.Annotations.NotNullAttribute;
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/JoinSequence.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/JoinSequence.cs
index 0b2677b82a..5646aeb921 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/JoinSequence.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/JoinSequence.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.05.18
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/NodeVisitor.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/NodeVisitor.cs
index f61ee2a21f..211b524d6b 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/NodeVisitor.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/NodeVisitor.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.23
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/ContainerNode.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/ContainerNode.cs
index afb1f1a8ab..4f4800686f 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/ContainerNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/ContainerNode.cs
@@ -2,11 +2,8 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Text;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/CycleNode.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/CycleNode.cs
index 2cb28479ae..69e1fc37c4 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/CycleNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/CycleNode.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.06
 
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/VariantNode.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/VariantNode.cs
index d799d1ebf9..690d704e58 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/VariantNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/Nodes/VariantNode.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.23
 
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/PostCompiler.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/PostCompiler.cs
index 84a4b1f6ee..ac8702cdef 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/PostCompiler.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/PostCompiler.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.04.23
 
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Text;
 
 namespace Xtensive.Sql.Compiler
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/Internals/RecursiveBinaryLogicExtractor.cs b/Orm/Xtensive.Orm/Sql/Compiler/Internals/RecursiveBinaryLogicExtractor.cs
index e71727a778..2b0c0bcfc5 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/Internals/RecursiveBinaryLogicExtractor.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/Internals/RecursiveBinaryLogicExtractor.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.08.29
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Compiler
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilationResult.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilationResult.cs
index 206d98aab9..dd801f8e62 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilationResult.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilationResult.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompiler.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompiler.cs
index 4e9f32eb6a..373717e19f 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompiler.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompiler.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerConfiguration.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerConfiguration.cs
index 6803971e96..23d48ad207 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerConfiguration.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerConfiguration.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.15
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using JetBrains.Annotations;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerContext.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerContext.cs
index f1f4554282..75caf68535 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerContext.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerContext.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerException.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerException.cs
index 5beadfb401..10623965c8 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerException.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerException.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingOptions.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingOptions.cs
index f892c75918..62c123b185 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingOptions.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingOptions.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.31
 
-using System;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingScope.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingScope.cs
index 62f20089c5..c1ec2982ee 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingScope.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerNamingScope.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.31
 
-using System;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerOutputScope.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerOutputScope.cs
index 64494fea5b..e4fe3b9815 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerOutputScope.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlCompilerOutputScope.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlParameterNameProvider.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlParameterNameProvider.cs
index f3b814e70a..8fcf89d05b 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlParameterNameProvider.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlParameterNameProvider.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.08.31
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Compiler
 {
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlPostCompilerConfiguration.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlPostCompilerConfiguration.cs
index 8e4b3d1815..0a2f1af627 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlPostCompilerConfiguration.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlPostCompilerConfiguration.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.07
 
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using JetBrains.Annotations;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlTableNameProvider.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlTableNameProvider.cs
index d19efc874a..6649341082 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlTableNameProvider.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlTableNameProvider.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Collections.Generic;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Compiler
diff --git a/Orm/Xtensive.Orm/Sql/Compiler/SqlTranslator.cs b/Orm/Xtensive.Orm/Sql/Compiler/SqlTranslator.cs
index 9eb356c69c..c9bea0456d 100644
--- a/Orm/Xtensive.Orm/Sql/Compiler/SqlTranslator.cs
+++ b/Orm/Xtensive.Orm/Sql/Compiler/SqlTranslator.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Text;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Sql/DbConnectionAccessorExtension.cs b/Orm/Xtensive.Orm/Sql/DbConnectionAccessorExtension.cs
index 1cc9e25a91..b097589004 100644
--- a/Orm/Xtensive.Orm/Sql/DbConnectionAccessorExtension.cs
+++ b/Orm/Xtensive.Orm/Sql/DbConnectionAccessorExtension.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System.Collections.Generic;
 using Xtensive.Orm;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAction.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAction.cs
index 4d14e86679..e3b7ee27cd 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAction.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAction.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Ddl
 {
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddColumn.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddColumn.cs
index 27e283db14..c014ed51bc 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddConstraint.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddConstraint.cs
index 2e09734d48..06fee61743 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAddConstraint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAlterIdentityInfo.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAlterIdentityInfo.cs
index b85cf78310..abcc96e6ad 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAlterIdentityInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlAlterIdentityInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlCascadableAction.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlCascadableAction.cs
index 006b6aa884..59543dbafe 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlCascadableAction.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlCascadableAction.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.10
 
-using System;
 
 namespace Xtensive.Sql.Ddl
 {
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropColumn.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropColumn.cs
index 1831f77e8b..9728f874e0 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropConstraint.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropConstraint.cs
index 613ce4b926..7e5be762e1 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropConstraint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropDefault.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropDefault.cs
index 7e97f2b28d..f994b0460c 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropDefault.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlDropDefault.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlRenameColumn.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlRenameColumn.cs
index 2e3a3d6d04..260933022e 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlRenameColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlRenameColumn.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.10
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlSetDefault.cs b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlSetDefault.cs
index 3bdefd8eab..907c7bd073 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlSetDefault.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Actions/SqlSetDefault.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterIdentityInfoOptions.cs b/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterIdentityInfoOptions.cs
index f15147d49e..6e1c2226b1 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterIdentityInfoOptions.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterIdentityInfoOptions.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Ddl
 {
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterPartitionFunctionOption.cs b/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterPartitionFunctionOption.cs
index 309a3da986..28f2dfb248 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterPartitionFunctionOption.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlAlterPartitionFunctionOption.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Ddl
 {
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlCommandType.cs b/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlCommandType.cs
index 39fc8462a9..39054dab11 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlCommandType.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/Misc/SqlCommandType.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.04
 
-using System;
 
 namespace Xtensive.Sql.Ddl
 {
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterDomain.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterDomain.cs
index 5417829627..1cd24aaa3a 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterDomain.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterDomain.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionFunction.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionFunction.cs
index e33de74791..0c2839cdc4 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionFunction.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionFunction.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionScheme.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionScheme.cs
index 49c5351c3b..80049645c5 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionScheme.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterPartitionScheme.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterSequence.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterSequence.cs
index 81cc21590d..e62113bd96 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterSequence.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterSequence.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterTable.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterTable.cs
index 14922811b9..99ddac75a1 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlAlterTable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCommand.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCommand.cs
index e45e92e1ae..e85b7469ea 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCommand.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCommand.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.04
 
-using System;
 
 namespace Xtensive.Sql.Ddl
 {
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateAssertion.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateAssertion.cs
index 7337e40a98..41a1647d3f 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateAssertion.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateAssertion.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCharcterSet.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCharcterSet.cs
index ebfe7235c2..b806917d11 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCharcterSet.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCharcterSet.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCollation.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCollation.cs
index e3f64791be..5f1cdfbe0f 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCollation.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateCollation.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateDomain.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateDomain.cs
index a45ae2d835..19e98cb66a 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateDomain.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateDomain.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateIndex.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateIndex.cs
index 48145b9118..e57759fda8 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateIndex.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateIndex.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Model;
 using Index = Xtensive.Sql.Model.Index;
 
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionFunction.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionFunction.cs
index 052000a2ed..6ee1bab361 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionFunction.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionFunction.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionScheme.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionScheme.cs
index 0b67b91f2d..360464be07 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionScheme.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreatePartitionScheme.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSchema.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSchema.cs
index 5790a5bcad..4041004459 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSchema.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSchema.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSequence.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSequence.cs
index bd6f2e1934..6415b3a0ea 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSequence.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateSequence.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTable.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTable.cs
index 4f1a162c5b..43b4ab6e81 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTranslation.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTranslation.cs
index 69eddc8832..aa2a95903a 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTranslation.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateTranslation.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateView.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateView.cs
index 08d7833ca8..9c8aad1fb0 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateView.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlCreateView.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropAssertion.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropAssertion.cs
index b045504b48..1dfc05e2e9 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropAssertion.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropAssertion.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCharacterSet.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCharacterSet.cs
index ffdddda616..363123e795 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCharacterSet.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCharacterSet.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCollation.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCollation.cs
index 555c35eef9..26d8865699 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCollation.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropCollation.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropDomain.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropDomain.cs
index a78ff5177a..4a105b43ce 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropDomain.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropDomain.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropIndex.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropIndex.cs
index cae7ed9e1e..529f4936d8 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropIndex.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropIndex.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Model;
 using Index = Xtensive.Sql.Model.Index;
 
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionFunction.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionFunction.cs
index c015b61950..7aa8e379a6 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionFunction.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionFunction.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionScheme.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionScheme.cs
index e315b7cd71..2937e54b20 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionScheme.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropPartitionScheme.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSchema.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSchema.cs
index b13f79a915..c4c879174d 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSchema.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSchema.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSequence.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSequence.cs
index 04d3d471d8..b75a8403d8 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSequence.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropSequence.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTable.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTable.cs
index 0d6df7110b..61780f4fe3 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTranslation.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTranslation.cs
index 533408563a..506aacd04f 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTranslation.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropTranslation.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropView.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropView.cs
index 93dd289bf8..aa7d6aeecf 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlDropView.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlDropView.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlRenameTable.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlRenameTable.cs
index 5474d4ca4c..f277bf527f 100644
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlRenameTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlRenameTable.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.10
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Ddl/SqlTruncateTable.cs b/Orm/Xtensive.Orm/Sql/Ddl/SqlTruncateTable.cs
index 857b19c9b9..115d847afb 100755
--- a/Orm/Xtensive.Orm/Sql/Ddl/SqlTruncateTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Ddl/SqlTruncateTable.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Ddl
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlColumnCollection.cs b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlColumnCollection.cs
index 17d856871b..1a362fd66e 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlColumnCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlColumnCollection.cs
@@ -2,9 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlInsertValuesCollection.cs b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlInsertValuesCollection.cs
index 62347d57bd..71ddff537d 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlInsertValuesCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlInsertValuesCollection.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml.Collections
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlOrderCollection.cs b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlOrderCollection.cs
index 4e3dd31afb..fb59263290 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlOrderCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlOrderCollection.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlTableColumnCollection.cs b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlTableColumnCollection.cs
index e03d3eaa45..5ce6c13175 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlTableColumnCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Collections/SqlTableColumnCollection.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlAggregate.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlAggregate.cs
index 860888f7fe..d7a9bbe251 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlAggregate.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlAggregate.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray.cs
index 983735ee01..d1f6f50abb 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.13
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray{T}.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray{T}.cs
index 7d33b219e6..670f3ba5ee 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray{T}.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlArray{T}.cs
@@ -2,9 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBetween.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBetween.cs
index fa04b0d05d..b986d006a1 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBetween.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBetween.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBinary.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBinary.cs
index bfcfe9e69d..79061f62f5 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBinary.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlBinary.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCase.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCase.cs
index 0fd704dfc6..9eab2de360 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCase.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCase.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCast.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCast.cs
index 950a5ec476..7e5965b163 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCast.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCast.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCollate.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCollate.cs
index 7f13e962b5..ba9479fb9d 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCollate.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCollate.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumn.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumn.cs
index aa2cc9aad4..8ced60482c 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnRef.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnRef.cs
index 6e22a11832..4cead51e5d 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnRef.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnRef.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnStub.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnStub.cs
index 9de632ef43..f1f57dcc2f 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnStub.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlColumnStub.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.08
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlComment.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlComment.cs
index 8f501e8ce5..b79f04befe 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlComment.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlComment.cs
@@ -4,7 +4,6 @@
 // Created by: Edgar Isajanyan
 // Created:    2021.09.13
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlConcat.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlConcat.cs
index cc8eec9be1..8186809f9e 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlConcat.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlConcat.cs
@@ -4,8 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.09.01
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlContainer.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlContainer.cs
index 9e9554c7de..e04fb9bf29 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlContainer.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlContainer.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.11
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCursor.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCursor.cs
index cd1b59c6b1..81bc1441f9 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCursor.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCursor.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCustomFunctionCall.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCustomFunctionCall.cs
index 35ac62ab61..d549e9cd80 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCustomFunctionCall.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlCustomFunctionCall.cs
@@ -4,10 +4,7 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.06
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDefaultValue.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDefaultValue.cs
index b95b79dbfe..11f81a953d 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDefaultValue.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDefaultValue.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDynamicFilter.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDynamicFilter.cs
index 132a527e6e..3f2f984ed1 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDynamicFilter.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlDynamicFilter.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.11.06
 
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpression.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpression.cs
index f7a174e5b6..fcf3339d75 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpression.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpression.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpressionList.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpressionList.cs
index 16ae8026b1..a356a021f6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpressionList.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExpressionList.cs
@@ -5,7 +5,6 @@
 // Created:    2009.09.01
 
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExtract.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExtract.cs
index c5ee6c3a7a..9eb8206ef6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExtract.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlExtract.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.24
 
-using System;
 using System.Diagnostics;
 using System.Reflection;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCall.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCall.cs
index 3801322b4c..e3c0dd6be2 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCall.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCall.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCallBase.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCallBase.cs
index 680fb1c61b..62310719c4 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCallBase.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlFunctionCallBase.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLike.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLike.cs
index d8892e0a0c..4e8fcbe532 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLike.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLike.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral.cs
index 95b6815fe6..87b2d60fd9 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.13
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral{T}.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral{T}.cs
index 6dae46acbe..9b91ff5d69 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral{T}.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlLiteral{T}.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlMatch.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlMatch.cs
index 602860db97..cd82d19daa 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlMatch.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlMatch.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNative.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNative.cs
index 26d7e11cbd..b50e953494 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNative.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNative.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNextValue.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNextValue.cs
index 7d4f714b93..b8863b5251 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNextValue.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNextValue.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNull.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNull.cs
index 9dfade6104..1af0c395cc 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNull.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlNull.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlParameterRef.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlParameterRef.cs
index 922305ac64..4aacbce91b 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlParameterRef.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlParameterRef.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRound.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRound.cs
index cf2a47879e..4b53e28081 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRound.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRound.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.03
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRow.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRow.cs
index d3058bedb9..733d161fc2 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRow.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlRow.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlSubQuery.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlSubQuery.cs
index d8cefb1d25..0b610d28e8 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlSubQuery.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlSubQuery.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTableColumn.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTableColumn.cs
index ee2d31dc7b..41a8293fb1 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTableColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTableColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTrim.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTrim.cs
index 038b1424ba..f2668d6eb8 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTrim.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlTrim.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUnary.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUnary.cs
index cf64055633..e103cfdfad 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUnary.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUnary.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserColumn.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserColumn.cs
index d439fabfe7..d2cbfab6e7 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserFunctionCall.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserFunctionCall.cs
index 980c3e4e84..af2447011f 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserFunctionCall.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlUserFunctionCall.cs
@@ -2,10 +2,7 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlVariable.cs b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlVariable.cs
index fc05321836..182b3a2617 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlVariable.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlVariable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Extensions.cs b/Orm/Xtensive.Orm/Sql/Dml/Extensions.cs
index 6f50752475..5c89fd5d36 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Extensions.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Extensions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.24
 
-using System;
 using System.Text;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlFastFirstRowsHint.cs b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlFastFirstRowsHint.cs
index 005a21d50a..164c22773c 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlFastFirstRowsHint.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlFastFirstRowsHint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlForceJoinOrderHint.cs b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlForceJoinOrderHint.cs
index df69681df2..c54278a1d6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlForceJoinOrderHint.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlForceJoinOrderHint.cs
@@ -2,9 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlHint.cs b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlHint.cs
index 0604b84565..7c7b9adf74 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlHint.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlHint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinHint.cs b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinHint.cs
index 0a03a6478c..40ffd72d2e 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinHint.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinHint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinMethod.cs b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinMethod.cs
index 07eb3f7096..8ce0a3c5a6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinMethod.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlJoinMethod.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlNativeHint.cs b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlNativeHint.cs
index 3334f448ea..fa28f58291 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlNativeHint.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Hints/SqlNativeHint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlContainsTable.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlContainsTable.cs
index e2d84cb178..9940e81c84 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlContainsTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlContainsTable.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlCustomFunctionType.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlCustomFunctionType.cs
index 5f2798c77f..35c427fa05 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlCustomFunctionType.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlCustomFunctionType.cs
@@ -4,7 +4,6 @@
 // Created by: Alena Mikshina
 // Created:    2014.05.06
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlDatePart.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlDatePart.cs
index 9a80a01cf2..5e9b404135 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlDatePart.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlDatePart.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimeOffsetPart.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimeOffsetPart.cs
index c1d0b61a9c..3b3dbbd7f9 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimeOffsetPart.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimeOffsetPart.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimePart.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimePart.cs
index e431858e08..9abaef0c7c 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimePart.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlDateTimePart.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlFetchOption.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlFetchOption.cs
index 2d7b4523d5..ea0ee6810d 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlFetchOption.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlFetchOption.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlFreeTextTable.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlFreeTextTable.cs
index 4dcb18621d..b31a92f7a2 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlFreeTextTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlFreeTextTable.cs
@@ -4,9 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2009.12.29
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Sql.Model;
 
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlFunctionType.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlFunctionType.cs
index a54c7e0456..ca407697ca 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlFunctionType.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlFunctionType.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlIntervalPart.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlIntervalPart.cs
index 45e6a7dbb4..24cd1a6e3e 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlIntervalPart.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlIntervalPart.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.02.25
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlJoinExpression.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlJoinExpression.cs
index 5c0cb91934..e147ca940e 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlJoinExpression.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlJoinExpression.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlJoinType.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlJoinType.cs
index 26c9be5935..b07059f9ba 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlJoinType.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlJoinType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlJoinedTable.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlJoinedTable.cs
index 28809f0efe..7847f5126c 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlJoinedTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlJoinedTable.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlLockType.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlLockType.cs
index a97c27a46a..24ec0b9671 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlLockType.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlLockType.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.24
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlMatchType.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlMatchType.cs
index abdc1feac4..f3630c5c27 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlMatchType.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlMatchType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlOrder.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlOrder.cs
index 4190c3540c..df38c3b3d7 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlOrder.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlOrder.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlQueryRef.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlQueryRef.cs
index e518a5eb22..352eecf104 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlQueryRef.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlQueryRef.cs
@@ -2,9 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlTable.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlTable.cs
index ad33aa6756..9ad3fd6192 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlTable.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Sql.Model;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlTableRef.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlTableRef.cs
index 5046adb0bb..93d8c054db 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlTableRef.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlTableRef.cs
@@ -2,9 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Linq;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Collections;
 using Xtensive.Sql.Model;
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlTimePart.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlTimePart.cs
index 87923501a7..8c4d2c7fa6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlTimePart.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlTimePart.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/SqlTrimType.cs b/Orm/Xtensive.Orm/Sql/Dml/SqlTrimType.cs
index 9fb89bb6d9..03a9060978 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/SqlTrimType.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/SqlTrimType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlAssignment.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlAssignment.cs
index 48df59268c..f8de3f75c2 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlAssignment.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlAssignment.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBatch.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBatch.cs
index 0dc6a9075b..ff06a870a9 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBatch.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBatch.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBreak.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBreak.cs
index 43fa616ea2..ca42e547f6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBreak.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlBreak.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlCloseCursor.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlCloseCursor.cs
index 6cbedc1c78..bdc1890ffd 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlCloseCursor.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlCloseCursor.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlContinue.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlContinue.cs
index 3b1ef9a5cc..970c2ff89a 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlContinue.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlContinue.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareCursor.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareCursor.cs
index 9508ff5bee..24c24339db 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareCursor.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareCursor.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareVariable.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareVariable.cs
index d7aa658f9f..66bd2507e6 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareVariable.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDeclareVariable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDelete.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDelete.cs
index 658b98a96f..15fb7cba1a 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDelete.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlDelete.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlFetch.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlFetch.cs
index 84adf61b29..0bfe5352da 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlFetch.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlFetch.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlIf.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlIf.cs
index ea2bbee211..1136746f31 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlIf.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlIf.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlInsert.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlInsert.cs
index 31c8df6523..4a20f9ba88 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlInsert.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlInsert.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Sql.Dml.Collections;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlOpenCursor.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlOpenCursor.cs
index ba33a97afe..36644b31bd 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlOpenCursor.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlOpenCursor.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryExpression.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryExpression.cs
index 4db55cfc43..d24be287c1 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryExpression.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryExpression.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryStatement.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryStatement.cs
index 81a13268ff..b27f53053b 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryStatement.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlQueryStatement.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlSelect.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlSelect.cs
index d4ea0f54a8..9ae76d6784 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlSelect.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlSelect.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlStatementBlock.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlStatementBlock.cs
index 7adecc9d10..7ce1ad75de 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlStatementBlock.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlStatementBlock.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlUpdate.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlUpdate.cs
index a0b0c62455..e890565436 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlUpdate.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlUpdate.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Dml
 {
diff --git a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlWhile.cs b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlWhile.cs
index 2b0a64748d..2cd2a33045 100644
--- a/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlWhile.cs
+++ b/Orm/Xtensive.Orm/Sql/Dml/Statements/SqlWhile.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml
diff --git a/Orm/Xtensive.Orm/Sql/Info/ColumnFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/ColumnFeatures.cs
index c92ec959b9..e3a0178664 100644
--- a/Orm/Xtensive.Orm/Sql/Info/ColumnFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/ColumnFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/ColumnInfo.cs b/Orm/Xtensive.Orm/Sql/Info/ColumnInfo.cs
index 00a4d28312..db8d7849c2 100644
--- a/Orm/Xtensive.Orm/Sql/Info/ColumnInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/ColumnInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintFeatures.cs
index 858c83e2c6..c13e256c7b 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintFeatures.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.20
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintInfo.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintInfo.cs
index 58ca7b7917..5ebbcd964e 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/CheckConstraintInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintActions.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintActions.cs
index b9c32a9e15..3da719dc67 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintActions.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintActions.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintFeatures.cs
index 4ca5442c9b..2238480472 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintFeatures.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.20
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintInfo.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintInfo.cs
index 127127e97a..0be608dc45 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/ForeignKeyConstraintInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/PrimaryKeyConstraintFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/PrimaryKeyConstraintFeatures.cs
index d5b16591d5..2992e7d473 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/PrimaryKeyConstraintFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/PrimaryKeyConstraintFeatures.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.20
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/Constaints/UniqueConstraintFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/Constaints/UniqueConstraintFeatures.cs
index f33c25986a..997436482a 100644
--- a/Orm/Xtensive.Orm/Sql/Info/Constaints/UniqueConstraintFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/Constaints/UniqueConstraintFeatures.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.20
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/CoreServerInfo.cs b/Orm/Xtensive.Orm/Sql/Info/CoreServerInfo.cs
index b08f385018..fc2d907251 100644
--- a/Orm/Xtensive.Orm/Sql/Info/CoreServerInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/CoreServerInfo.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.25
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/DataTypeCollection.cs b/Orm/Xtensive.Orm/Sql/Info/DataTypeCollection.cs
index 4ed8885b9e..3920861d64 100644
--- a/Orm/Xtensive.Orm/Sql/Info/DataTypeCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/DataTypeCollection.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/DataTypeFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/DataTypeFeatures.cs
index 252440a479..5d71ad26f0 100644
--- a/Orm/Xtensive.Orm/Sql/Info/DataTypeFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/DataTypeFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/DataTypeInfo.cs b/Orm/Xtensive.Orm/Sql/Info/DataTypeInfo.cs
index 23cacaa9c9..19c4831528 100644
--- a/Orm/Xtensive.Orm/Sql/Info/DataTypeInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/DataTypeInfo.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Sql/Info/DdlStatements.cs b/Orm/Xtensive.Orm/Sql/Info/DdlStatements.cs
index f76cf9306f..7f62d2925d 100644
--- a/Orm/Xtensive.Orm/Sql/Info/DdlStatements.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/DdlStatements.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/FeaturesExtensions.cs b/Orm/Xtensive.Orm/Sql/Info/FeaturesExtensions.cs
index 04dd1c8fa9..ba36793726 100644
--- a/Orm/Xtensive.Orm/Sql/Info/FeaturesExtensions.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/FeaturesExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.15
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/FullTextSearchInfo.cs b/Orm/Xtensive.Orm/Sql/Info/FullTextSearchInfo.cs
index c3d1b52a6e..344080a13b 100644
--- a/Orm/Xtensive.Orm/Sql/Info/FullTextSearchInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/FullTextSearchInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/IdentityFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/IdentityFeatures.cs
index 0876e94ff3..77d0a89204 100644
--- a/Orm/Xtensive.Orm/Sql/Info/IdentityFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/IdentityFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/IndexFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/IndexFeatures.cs
index f955b75f57..fa9bd7ef1d 100644
--- a/Orm/Xtensive.Orm/Sql/Info/IndexFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/IndexFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/IndexInfo.cs b/Orm/Xtensive.Orm/Sql/Info/IndexInfo.cs
index 6a9e1c3304..7f56c38ddc 100644
--- a/Orm/Xtensive.Orm/Sql/Info/IndexInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/IndexInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/IsolationLevels.cs b/Orm/Xtensive.Orm/Sql/Info/IsolationLevels.cs
index 2532baad46..d29e8c231a 100644
--- a/Orm/Xtensive.Orm/Sql/Info/IsolationLevels.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/IsolationLevels.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/PartitionMethods.cs b/Orm/Xtensive.Orm/Sql/Info/PartitionMethods.cs
index a246b6f421..685806b91d 100644
--- a/Orm/Xtensive.Orm/Sql/Info/PartitionMethods.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/PartitionMethods.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/QueryFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/QueryFeatures.cs
index 76773ed2d8..6f79eb99a9 100644
--- a/Orm/Xtensive.Orm/Sql/Info/QueryFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/QueryFeatures.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/QueryInfo.cs b/Orm/Xtensive.Orm/Sql/Info/QueryInfo.cs
index 143253c7fa..b16441994b 100644
--- a/Orm/Xtensive.Orm/Sql/Info/QueryInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/QueryInfo.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/SequenceFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/SequenceFeatures.cs
index f07dc9c6a1..80b30f5285 100644
--- a/Orm/Xtensive.Orm/Sql/Info/SequenceFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/SequenceFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/SequenceInfo.cs b/Orm/Xtensive.Orm/Sql/Info/SequenceInfo.cs
index aab12fe5f0..03914805cf 100644
--- a/Orm/Xtensive.Orm/Sql/Info/SequenceInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/SequenceInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/ServerFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/ServerFeatures.cs
index 684308c5b7..8b0023e8cf 100644
--- a/Orm/Xtensive.Orm/Sql/Info/ServerFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/ServerFeatures.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2010.02.05
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/TableInfo.cs b/Orm/Xtensive.Orm/Sql/Info/TableInfo.cs
index bb521b3e19..68330c2b23 100644
--- a/Orm/Xtensive.Orm/Sql/Info/TableInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/TableInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/TemporaryTableFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/TemporaryTableFeatures.cs
index 9df1a79ca3..4c039035e1 100644
--- a/Orm/Xtensive.Orm/Sql/Info/TemporaryTableFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/TemporaryTableFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Info/TemporaryTableInfo.cs b/Orm/Xtensive.Orm/Sql/Info/TemporaryTableInfo.cs
index 3a332a5b51..fcd9d72098 100644
--- a/Orm/Xtensive.Orm/Sql/Info/TemporaryTableInfo.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/TemporaryTableInfo.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/ValueRange.cs b/Orm/Xtensive.Orm/Sql/Info/ValueRange.cs
index 7e089a1130..6f30a086e8 100644
--- a/Orm/Xtensive.Orm/Sql/Info/ValueRange.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/ValueRange.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.07
 
-using System;
 using System.Diagnostics;
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/ValueRange{T}.cs b/Orm/Xtensive.Orm/Sql/Info/ValueRange{T}.cs
index ee75aac271..82f7b100ba 100644
--- a/Orm/Xtensive.Orm/Sql/Info/ValueRange{T}.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/ValueRange{T}.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 
 namespace Xtensive.Sql.Info
diff --git a/Orm/Xtensive.Orm/Sql/Info/ViewFeatures.cs b/Orm/Xtensive.Orm/Sql/Info/ViewFeatures.cs
index 37426b22b8..4f3b89f1bf 100644
--- a/Orm/Xtensive.Orm/Sql/Info/ViewFeatures.cs
+++ b/Orm/Xtensive.Orm/Sql/Info/ViewFeatures.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Info
 {
diff --git a/Orm/Xtensive.Orm/Sql/Interfaces/ILargeObject.cs b/Orm/Xtensive.Orm/Sql/Interfaces/ILargeObject.cs
index 42158cc1c3..dc1ea59034 100644
--- a/Orm/Xtensive.Orm/Sql/Interfaces/ILargeObject.cs
+++ b/Orm/Xtensive.Orm/Sql/Interfaces/ILargeObject.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.08.11
 
-using System;
 using System.Data.Common;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/Interfaces/ISqlNode.cs b/Orm/Xtensive.Orm/Sql/Interfaces/ISqlNode.cs
index cbdeb2e6ec..a80313bd9e 100644
--- a/Orm/Xtensive.Orm/Sql/Interfaces/ISqlNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Interfaces/ISqlNode.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/Interfaces/ISqlQueryExpression.cs b/Orm/Xtensive.Orm/Sql/Interfaces/ISqlQueryExpression.cs
index 8f23066403..6c2a866798 100644
--- a/Orm/Xtensive.Orm/Sql/Interfaces/ISqlQueryExpression.cs
+++ b/Orm/Xtensive.Orm/Sql/Interfaces/ISqlQueryExpression.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System.Collections.Generic;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/Internals/SqlNodeCloneContext.cs b/Orm/Xtensive.Orm/Sql/Internals/SqlNodeCloneContext.cs
index a67f025d1f..2c48205f8e 100644
--- a/Orm/Xtensive.Orm/Sql/Internals/SqlNodeCloneContext.cs
+++ b/Orm/Xtensive.Orm/Sql/Internals/SqlNodeCloneContext.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/Internals/SqlValidator.cs b/Orm/Xtensive.Orm/Sql/Internals/SqlValidator.cs
index a42e9cbadd..321a188516 100644
--- a/Orm/Xtensive.Orm/Sql/Internals/SqlValidator.cs
+++ b/Orm/Xtensive.Orm/Sql/Internals/SqlValidator.cs
@@ -2,9 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Sql/Model/Action.cs b/Orm/Xtensive.Orm/Sql/Model/Action.cs
index 95200cfa25..148f350cf0 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Action.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Action.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/BoundaryType.cs b/Orm/Xtensive.Orm/Sql/Model/BoundaryType.cs
index 7b39da0ea1..9f59ac6656 100644
--- a/Orm/Xtensive.Orm/Sql/Model/BoundaryType.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/BoundaryType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Catalog.cs b/Orm/Xtensive.Orm/Sql/Model/Catalog.cs
index c3c66c4b8f..23db71c7e2 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Catalog.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Catalog.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/CatalogNode.cs b/Orm/Xtensive.Orm/Sql/Model/CatalogNode.cs
index e3e1e3ac8a..1c6264bc4f 100644
--- a/Orm/Xtensive.Orm/Sql/Model/CatalogNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/CatalogNode.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/CharacterSet.cs b/Orm/Xtensive.Orm/Sql/Model/CharacterSet.cs
index f173e786d3..ea15ce0d71 100644
--- a/Orm/Xtensive.Orm/Sql/Model/CharacterSet.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/CharacterSet.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/CheckOptions.cs b/Orm/Xtensive.Orm/Sql/Model/CheckOptions.cs
index 4967498c5e..26961b2fdb 100644
--- a/Orm/Xtensive.Orm/Sql/Model/CheckOptions.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/CheckOptions.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Collation.cs b/Orm/Xtensive.Orm/Sql/Model/Collation.cs
index 5038e26887..ca33542c43 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Collation.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Collation.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/Assertion.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/Assertion.cs
index 48f6713161..78aeea471d 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/Assertion.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/Assertion.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/CheckConstraint.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/CheckConstraint.cs
index 4731c33669..9c2e37351d 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/CheckConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/CheckConstraint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/Constraint.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/Constraint.cs
index 4723e2dca7..fb965dcaa9 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/Constraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/Constraint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/DefaultConstraint.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/DefaultConstraint.cs
index d866545bcc..9cbe03c7cd 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/DefaultConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/DefaultConstraint.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.06.07
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/DomainConstraint.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/DomainConstraint.cs
index ab2502749d..952e22f9a5 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/DomainConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/DomainConstraint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/ForeignKey.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/ForeignKey.cs
index a411e1bbcb..81cd978425 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/ForeignKey.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/ForeignKey.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/PrimaryKey.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/PrimaryKey.cs
index 9ca9d85ef9..362a80ca1f 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/PrimaryKey.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/PrimaryKey.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/TableConstraint.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/TableConstraint.cs
index 5b10514197..b87a57033e 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/TableConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/TableConstraint.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Sql.Dml;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Constraints/UniqueConstraint.cs b/Orm/Xtensive.Orm/Sql/Model/Constraints/UniqueConstraint.cs
index bbaabde174..98c4dbb3bf 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Constraints/UniqueConstraint.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Constraints/UniqueConstraint.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Collections;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/DataTable.cs b/Orm/Xtensive.Orm/Sql/Model/DataTable.cs
index dd1826e8d8..170ec7c254 100644
--- a/Orm/Xtensive.Orm/Sql/Model/DataTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/DataTable.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/DataTableColumn.cs b/Orm/Xtensive.Orm/Sql/Model/DataTableColumn.cs
index bebaf04825..94705c0770 100644
--- a/Orm/Xtensive.Orm/Sql/Model/DataTableColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/DataTableColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/DataTableNode.cs b/Orm/Xtensive.Orm/Sql/Model/DataTableNode.cs
index f2989807f5..d91ce10198 100644
--- a/Orm/Xtensive.Orm/Sql/Model/DataTableNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/DataTableNode.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Domain.cs b/Orm/Xtensive.Orm/Sql/Model/Domain.cs
index 660cf1f1d4..7a372e4720 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Domain.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Domain.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/Extractor.cs b/Orm/Xtensive.Orm/Sql/Model/Extractor.cs
index ecf1b961ad..ca1adbb5f7 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Extractor.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Extractor.cs
@@ -3,8 +3,6 @@
 // See the License.txt file in the project root for more information.
 
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/FullTextIndex.cs b/Orm/Xtensive.Orm/Sql/Model/FullTextIndex.cs
index 4cc843da5a..0f800c4248 100644
--- a/Orm/Xtensive.Orm/Sql/Model/FullTextIndex.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/FullTextIndex.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2010.01.14
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Index.cs b/Orm/Xtensive.Orm/Sql/Model/Index.cs
index 8731bc0249..34efc78251 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Index.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Index.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/IndexColumn.cs b/Orm/Xtensive.Orm/Sql/Model/IndexColumn.cs
index 28ae805d1e..26f526ddd4 100644
--- a/Orm/Xtensive.Orm/Sql/Model/IndexColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/IndexColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/Interfaces/IConstrainable.cs b/Orm/Xtensive.Orm/Sql/Model/Interfaces/IConstrainable.cs
index 273004ec82..6d2adeb132 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Interfaces/IConstrainable.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Interfaces/IConstrainable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Interfaces/IPermission.cs b/Orm/Xtensive.Orm/Sql/Model/Interfaces/IPermission.cs
index fd2bdce555..4d98247d62 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Interfaces/IPermission.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Interfaces/IPermission.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System.Collections.Generic;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Language.cs b/Orm/Xtensive.Orm/Sql/Model/Language.cs
index 2c6ec0ae49..b1088d2c8d 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Language.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Language.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Gamzov
 // Created:    2010.01.25
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Node.cs b/Orm/Xtensive.Orm/Sql/Model/Node.cs
index 07927af311..b3ae243161 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Node.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Node.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/NodeCollection.cs b/Orm/Xtensive.Orm/Sql/Model/NodeCollection.cs
index bd594c18f2..8816f49446 100644
--- a/Orm/Xtensive.Orm/Sql/Model/NodeCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/NodeCollection.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Sql/Model/PairedNodeCollection.cs b/Orm/Xtensive.Orm/Sql/Model/PairedNodeCollection.cs
index 80dd0fa13c..c3beacd99b 100644
--- a/Orm/Xtensive.Orm/Sql/Model/PairedNodeCollection.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/PairedNodeCollection.cs
@@ -2,9 +2,7 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/PartitionMethod.cs b/Orm/Xtensive.Orm/Sql/Model/PartitionMethod.cs
index 0d4a51e2b0..7c2ca7c795 100644
--- a/Orm/Xtensive.Orm/Sql/Model/PartitionMethod.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/PartitionMethod.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/HashPartition.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/HashPartition.cs
index 5858acf706..c37944d370 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/HashPartition.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/HashPartition.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/ListPartition.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/ListPartition.cs
index 88722254ba..6bb5a30e82 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/ListPartition.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/ListPartition.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/Partition.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/Partition.cs
index 739775ea40..1971e4e0ed 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/Partition.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/Partition.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionDescriptor.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionDescriptor.cs
index d26a9ebecd..7fba601823 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionDescriptor.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionDescriptor.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionFunction.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionFunction.cs
index 91a8be6291..ddb3e7863f 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionFunction.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionFunction.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionSchema.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionSchema.cs
index f808c31060..6ddb83adc7 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionSchema.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/PartitionSchema.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/Partitioning/RangePartition.cs b/Orm/Xtensive.Orm/Sql/Model/Partitioning/RangePartition.cs
index 8bf1bfcf75..f47fec79e1 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Partitioning/RangePartition.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Partitioning/RangePartition.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/ReferentialAction.cs b/Orm/Xtensive.Orm/Sql/Model/ReferentialAction.cs
index 398012aa36..798ed36672 100644
--- a/Orm/Xtensive.Orm/Sql/Model/ReferentialAction.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/ReferentialAction.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Schema.cs b/Orm/Xtensive.Orm/Sql/Model/Schema.cs
index da71e0a5fc..8c81c324c8 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Schema.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Schema.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/SchemaNode.cs b/Orm/Xtensive.Orm/Sql/Model/SchemaNode.cs
index 497d81cf6d..839cb5e8d0 100644
--- a/Orm/Xtensive.Orm/Sql/Model/SchemaNode.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/SchemaNode.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Sequence.cs b/Orm/Xtensive.Orm/Sql/Model/Sequence.cs
index 3dcecaf34c..52037f6689 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Sequence.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Sequence.cs
@@ -2,7 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/SequenceDescriptor.cs b/Orm/Xtensive.Orm/Sql/Model/SequenceDescriptor.cs
index 7817a69373..2cef2b93e7 100644
--- a/Orm/Xtensive.Orm/Sql/Model/SequenceDescriptor.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/SequenceDescriptor.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/SpatialIndex.cs b/Orm/Xtensive.Orm/Sql/Model/SpatialIndex.cs
index 0ce8622e75..566467615d 100644
--- a/Orm/Xtensive.Orm/Sql/Model/SpatialIndex.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/SpatialIndex.cs
@@ -4,7 +4,6 @@
 // Created by: Dmitri Maximov
 // Created:    2011.09.25
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/SqlModelVisitor.cs b/Orm/Xtensive.Orm/Sql/Model/SqlModelVisitor.cs
index 9196ade659..a0d66887e0 100644
--- a/Orm/Xtensive.Orm/Sql/Model/SqlModelVisitor.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/SqlModelVisitor.cs
@@ -4,7 +4,6 @@
 // Created by: Ivan Galkin
 // Created:    2009.03.31
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/Table.cs b/Orm/Xtensive.Orm/Sql/Model/Table.cs
index e5b9455264..fc2549f1bf 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Table.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Table.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Sql/Model/TableColumn.cs b/Orm/Xtensive.Orm/Sql/Model/TableColumn.cs
index 1eb05cf3fe..fa117c9072 100644
--- a/Orm/Xtensive.Orm/Sql/Model/TableColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/TableColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Dml;
 
diff --git a/Orm/Xtensive.Orm/Sql/Model/TemporaryTable.cs b/Orm/Xtensive.Orm/Sql/Model/TemporaryTable.cs
index 7e0b601720..2aee98abbf 100644
--- a/Orm/Xtensive.Orm/Sql/Model/TemporaryTable.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/TemporaryTable.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/Model/Translation.cs b/Orm/Xtensive.Orm/Sql/Model/Translation.cs
index d87f3adc59..4c22566c00 100644
--- a/Orm/Xtensive.Orm/Sql/Model/Translation.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/Translation.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql.Model
 {
diff --git a/Orm/Xtensive.Orm/Sql/Model/View.cs b/Orm/Xtensive.Orm/Sql/Model/View.cs
index f8920b6d55..249d38e44c 100644
--- a/Orm/Xtensive.Orm/Sql/Model/View.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/View.cs
@@ -2,8 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Collections;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Sql/Model/ViewColumn.cs b/Orm/Xtensive.Orm/Sql/Model/ViewColumn.cs
index 350ff69dbe..e7ee2e0d26 100644
--- a/Orm/Xtensive.Orm/Sql/Model/ViewColumn.cs
+++ b/Orm/Xtensive.Orm/Sql/Model/ViewColumn.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Model
diff --git a/Orm/Xtensive.Orm/Sql/SqlConnection.cs b/Orm/Xtensive.Orm/Sql/SqlConnection.cs
index b1f0c9b3b8..b283002628 100644
--- a/Orm/Xtensive.Orm/Sql/SqlConnection.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlConnection.cs
@@ -2,12 +2,9 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.Runtime.CompilerServices;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Collections;
 using Xtensive.Core;
 using Xtensive.Orm;
diff --git a/Orm/Xtensive.Orm/Sql/SqlDdl.cs b/Orm/Xtensive.Orm/Sql/SqlDdl.cs
index 2a0351f111..811eb7f381 100644
--- a/Orm/Xtensive.Orm/Sql/SqlDdl.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlDdl.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.09
 
-using System;
 using Xtensive.Core;
 using Xtensive.Sql.Ddl;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Sql/SqlDml.cs b/Orm/Xtensive.Orm/Sql/SqlDml.cs
index d6dd3cb750..e5af28c0b8 100644
--- a/Orm/Xtensive.Orm/Sql/SqlDml.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlDml.cs
@@ -2,8 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Reflection;
 using Xtensive.Collections;
@@ -11,7 +9,6 @@
 using Xtensive.Reflection;
 using Xtensive.Sql.Dml;
 using Xtensive.Sql.Model;
-using System.Linq;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/SqlDriver.cs b/Orm/Xtensive.Orm/Sql/SqlDriver.cs
index 24dd3b1752..ff21f3de4e 100644
--- a/Orm/Xtensive.Orm/Sql/SqlDriver.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlDriver.cs
@@ -2,11 +2,6 @@
 // This code is distributed under MIT license terms.
 // See the License.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Sql/SqlDriverConfiguration.cs b/Orm/Xtensive.Orm/Sql/SqlDriverConfiguration.cs
index 7a7f0b5a9b..1618556c06 100644
--- a/Orm/Xtensive.Orm/Sql/SqlDriverConfiguration.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlDriverConfiguration.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.27
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm;
 
diff --git a/Orm/Xtensive.Orm/Sql/SqlDriverFactory.cs b/Orm/Xtensive.Orm/Sql/SqlDriverFactory.cs
index 14fd6c46fc..49dd106cfa 100644
--- a/Orm/Xtensive.Orm/Sql/SqlDriverFactory.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlDriverFactory.cs
@@ -5,8 +5,6 @@
 // Created:    2009.06.23
 
 using System.Data.Common;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm;
 using Xtensive.Sql.Info;
diff --git a/Orm/Xtensive.Orm/Sql/SqlExtensions.cs b/Orm/Xtensive.Orm/Sql/SqlExtensions.cs
index 0cdfb1d583..a2728ffc57 100644
--- a/Orm/Xtensive.Orm/Sql/SqlExtensions.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.30
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 using Xtensive.Orm;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Sql/SqlHelper.cs b/Orm/Xtensive.Orm/Sql/SqlHelper.cs
index c9e4a8151c..c60ad5c199 100644
--- a/Orm/Xtensive.Orm/Sql/SqlHelper.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlHelper.cs
@@ -4,13 +4,9 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.17
 
-using System;
-using System.Collections.Generic;
 using System.Data;
 using System.Data.Common;
 using System.Runtime.CompilerServices;
-using System.Threading;
-using System.Threading.Tasks;
 using Xtensive.Core;
 using Xtensive.Orm;
 using Xtensive.Sql.Dml;
diff --git a/Orm/Xtensive.Orm/Sql/SqlNode.cs b/Orm/Xtensive.Orm/Sql/SqlNode.cs
index 293f94fc94..b0669710c2 100644
--- a/Orm/Xtensive.Orm/Sql/SqlNode.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlNode.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/SqlNodeType.cs b/Orm/Xtensive.Orm/Sql/SqlNodeType.cs
index f066f9a8f2..f578f7543d 100644
--- a/Orm/Xtensive.Orm/Sql/SqlNodeType.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlNodeType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/SqlStatement.cs b/Orm/Xtensive.Orm/Sql/SqlStatement.cs
index 49a5f7d0d9..c839c7a33d 100644
--- a/Orm/Xtensive.Orm/Sql/SqlStatement.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlStatement.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/SqlType.cs b/Orm/Xtensive.Orm/Sql/SqlType.cs
index 895a17a3b5..a64727d7a4 100644
--- a/Orm/Xtensive.Orm/Sql/SqlType.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 
 namespace Xtensive.Sql
 {
diff --git a/Orm/Xtensive.Orm/Sql/SqlValueType.cs b/Orm/Xtensive.Orm/Sql/SqlValueType.cs
index 160871d4c9..302e01f42a 100644
--- a/Orm/Xtensive.Orm/Sql/SqlValueType.cs
+++ b/Orm/Xtensive.Orm/Sql/SqlValueType.cs
@@ -2,7 +2,6 @@
 // All rights reserved.
 // For conditions of distribution and use, see license.
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/CustomTypeMapper.cs b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/CustomTypeMapper.cs
index 30d8c0e8a6..87f0709020 100644
--- a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/CustomTypeMapper.cs
+++ b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/CustomTypeMapper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.07
 
-using System;
 using System.Data.Common;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapper.cs b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapper.cs
index 6d217e58c4..ad0affd1df 100644
--- a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapper.cs
+++ b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapper.cs
@@ -4,11 +4,9 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.06.19
 
-using System;
 using System.Data;
 using System.Data.Common;
 using System.IO;
-using System.Linq;
 using Xtensive.Sql.Info;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapping.cs b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapping.cs
index 61a94a1333..18c65ab7d5 100644
--- a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapping.cs
+++ b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMapping.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.03
 
-using System;
 using System.Data.Common;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistry.cs b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistry.cs
index 2b08bc0390..11d22bde08 100644
--- a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistry.cs
+++ b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistry.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.07.03
 
-using System;
-using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Linq;
 using Xtensive.Reflection;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistryBuilder.cs b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistryBuilder.cs
index 89e0fd7942..03234bf941 100644
--- a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistryBuilder.cs
+++ b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/TypeMappingRegistryBuilder.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.06.07
 
-using System;
-using System.Collections.Generic;
 using System.Data.Common;
-using System.Linq;
 using Xtensive.Core;
 
 namespace Xtensive.Sql
diff --git a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/ValueRangeValidator.cs b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/ValueRangeValidator.cs
index 75ec147732..6f48acec8c 100644
--- a/Orm/Xtensive.Orm/Sql/ValueTypeMapping/ValueRangeValidator.cs
+++ b/Orm/Xtensive.Orm/Sql/ValueTypeMapping/ValueRangeValidator.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2009.12.03
 
-using System;
 using Xtensive.Reflection;
 using Xtensive.Sql.Info;
 
diff --git a/Orm/Xtensive.Orm/Strings.Designer.cs b/Orm/Xtensive.Orm/Strings.Designer.cs
index 284d869e30..12a79c401c 100644
--- a/Orm/Xtensive.Orm/Strings.Designer.cs
+++ b/Orm/Xtensive.Orm/Strings.Designer.cs
@@ -9,7 +9,6 @@
 //------------------------------------------------------------------------------
 
 namespace Xtensive {
-    using System;
     
     
     /// <summary>
diff --git a/Orm/Xtensive.Orm/Tuples/DifferentialTuple.cs b/Orm/Xtensive.Orm/Tuples/DifferentialTuple.cs
index e221bd07f3..34b8fcfe40 100644
--- a/Orm/Xtensive.Orm/Tuples/DifferentialTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/DifferentialTuple.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.05.22
 
-using System;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Tuples/FastReadOnlyTuple.cs b/Orm/Xtensive.Orm/Tuples/FastReadOnlyTuple.cs
index 55c1f452a4..6587e98741 100644
--- a/Orm/Xtensive.Orm/Tuples/FastReadOnlyTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/FastReadOnlyTuple.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.11.01
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Interfaces/ITuple.cs b/Orm/Xtensive.Orm/Tuples/Interfaces/ITuple.cs
index 2def5c2010..0197dc0131 100644
--- a/Orm/Xtensive.Orm/Tuples/Interfaces/ITuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/Interfaces/ITuple.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.05.30
 
-using System;
 
 namespace Xtensive.Tuples
 {
diff --git a/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldAccessor.cs b/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldAccessor.cs
index abea03b209..fea9419be3 100644
--- a/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldAccessor.cs
+++ b/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldAccessor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.01.22
 
-using System;
 using System.Numerics;
 
 namespace Xtensive.Tuples.Packed
diff --git a/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldDescriptor.cs b/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldDescriptor.cs
index e97d0d27da..136b9bf2db 100644
--- a/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldDescriptor.cs
+++ b/Orm/Xtensive.Orm/Tuples/Packed/PackedFieldDescriptor.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.29
 
-using System;
 
 namespace Xtensive.Tuples.Packed
 {
diff --git a/Orm/Xtensive.Orm/Tuples/Packed/PackedTuple.cs b/Orm/Xtensive.Orm/Tuples/Packed/PackedTuple.cs
index 22185d43d8..864f7d05ff 100644
--- a/Orm/Xtensive.Orm/Tuples/Packed/PackedTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/Packed/PackedTuple.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.29
 
-using System;
 
 namespace Xtensive.Tuples.Packed
 {
diff --git a/Orm/Xtensive.Orm/Tuples/Packed/PackingOrderInfoComparer.cs b/Orm/Xtensive.Orm/Tuples/Packed/PackingOrderInfoComparer.cs
index d283fa272b..40072d59fc 100644
--- a/Orm/Xtensive.Orm/Tuples/Packed/PackingOrderInfoComparer.cs
+++ b/Orm/Xtensive.Orm/Tuples/Packed/PackingOrderInfoComparer.cs
@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 
 namespace Xtensive.Tuples.Packed
 {
diff --git a/Orm/Xtensive.Orm/Tuples/Packed/TupleLayout.cs b/Orm/Xtensive.Orm/Tuples/Packed/TupleLayout.cs
index 0eabb63263..a1e914d8d6 100644
--- a/Orm/Xtensive.Orm/Tuples/Packed/TupleLayout.cs
+++ b/Orm/Xtensive.Orm/Tuples/Packed/TupleLayout.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2012.12.29
 
-using System;
 using System.Runtime.CompilerServices;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Tuples/ReferencedTuple.cs b/Orm/Xtensive.Orm/Tuples/ReferencedTuple.cs
index 087cbfb9d0..85506a9107 100644
--- a/Orm/Xtensive.Orm/Tuples/ReferencedTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/ReferencedTuple.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Kofman
 // Created:    2009.04.03
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Tuples/RegularTuple.cs b/Orm/Xtensive.Orm/Tuples/RegularTuple.cs
index 05147fdfad..e0d5c8d9ad 100644
--- a/Orm/Xtensive.Orm/Tuples/RegularTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/RegularTuple.cs
@@ -4,7 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.01.24
 
-using System;
 using System.Runtime.Serialization;
 
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/CombineTransform.cs b/Orm/Xtensive.Orm/Tuples/Transform/CombineTransform.cs
index 210fa33d2d..f78ea4a76e 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/CombineTransform.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/CombineTransform.cs
@@ -4,10 +4,7 @@
 // Created by: Alexey Kochetov
 // Created:    2008.04.30
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform.cs b/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform.cs
index 222374fe97..0996468d02 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform.cs
@@ -4,10 +4,7 @@
 // Created by: Elena Vakhtina
 // Created:    20.06.2008
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform{T}.cs b/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform{T}.cs
index b8aaad88c5..d063f68085 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform{T}.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/CutInTransform{T}.cs
@@ -4,9 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    20.06.2008
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Xtensive.Collections;
 using Xtensive.Reflection;
 using Xtensive.Tuples.Transform;
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/CutOutTransform.cs b/Orm/Xtensive.Orm/Tuples/Transform/CutOutTransform.cs
index 34dfd1247e..7e0e5212c0 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/CutOutTransform.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/CutOutTransform.cs
@@ -4,7 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.07.07
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple.cs b/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple.cs
index 19628222ce..e911e0c7ff 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.07
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple1.cs b/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple1.cs
index 7e2ca9dd2b..26eac49ea3 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple1.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple1.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Core;
 
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple3.cs b/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple3.cs
index fae607272e..cb91e7a910 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple3.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/Internals/MapTransformTuple3.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.04
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/Internals/ReadOnlyTransformTuple.cs b/Orm/Xtensive.Orm/Tuples/Transform/Internals/ReadOnlyTransformTuple.cs
index 3cca08abf2..9442b6464e 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/Internals/ReadOnlyTransformTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/Internals/ReadOnlyTransformTuple.cs
@@ -4,8 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.06.15
 
-using System;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/MapTransform.cs b/Orm/Xtensive.Orm/Tuples/Transform/MapTransform.cs
index 0bed3c1f94..bfedfe1548 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/MapTransform.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/MapTransform.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.07
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Collections;
 using Xtensive.Core;
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/ReadOnlyTransform.cs b/Orm/Xtensive.Orm/Tuples/Transform/ReadOnlyTransform.cs
index b235e8d8b7..8a1160c310 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/ReadOnlyTransform.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/ReadOnlyTransform.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.02
 
-using System;
 using System.Diagnostics;
-using System.Linq;
 using Xtensive.Core;
 
 using Xtensive.Tuples.Transform.Internals;
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/SegmentTransform.cs b/Orm/Xtensive.Orm/Tuples/Transform/SegmentTransform.cs
index 4f04b02d50..59af74df5a 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/SegmentTransform.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/SegmentTransform.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.20
 
-using System;
 using System.Diagnostics;
 using Xtensive.Core;
 using Xtensive.Reflection;
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple.cs b/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple.cs
index 34a88c5e7d..5283ad6dc5 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple.cs
@@ -4,8 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.07
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple{TTupleTransform}.cs b/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple{TTupleTransform}.cs
index 54b7567ab1..6bf5d0f913 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple{TTupleTransform}.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/TransformedTuple{TTupleTransform}.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.04.30
 
-using System;
 using System.Diagnostics;
 
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformBase.cs b/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformBase.cs
index 00e2419167..d31de0aa79 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformBase.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformBase.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.04.30
 
-using System;
 using System.Diagnostics;
 using Xtensive.Reflection;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformType.cs b/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformType.cs
index 2a10b5e8f2..8994e1458b 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformType.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/TupleTransformType.cs
@@ -4,7 +4,6 @@
 // Created by: Alexey Kochetov
 // Created:    2008.05.06
 
-using System;
 
 namespace Xtensive.Tuples.Transform
 {
diff --git a/Orm/Xtensive.Orm/Tuples/Transform/WrappingTransformTupleBase.cs b/Orm/Xtensive.Orm/Tuples/Transform/WrappingTransformTupleBase.cs
index 5d2c9aba60..69873a662d 100644
--- a/Orm/Xtensive.Orm/Tuples/Transform/WrappingTransformTupleBase.cs
+++ b/Orm/Xtensive.Orm/Tuples/Transform/WrappingTransformTupleBase.cs
@@ -4,8 +4,6 @@
 // Created by: Alex Yakunin
 // Created:    2008.06.02
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/Tuple.cs b/Orm/Xtensive.Orm/Tuples/Tuple.cs
index a6ea9ecf76..bd6346adfb 100644
--- a/Orm/Xtensive.Orm/Tuples/Tuple.cs
+++ b/Orm/Xtensive.Orm/Tuples/Tuple.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.05.30
 
-using System;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Runtime.Serialization;
diff --git a/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs b/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs
index e0bd7acd0a..37429b6692 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs
@@ -5,9 +5,7 @@
 // Created:    2007.05.30
 
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.Serialization;
 using System.Text;
diff --git a/Orm/Xtensive.Orm/Tuples/TupleExtensions.cs b/Orm/Xtensive.Orm/Tuples/TupleExtensions.cs
index b6e382dae0..5b37aa1e3a 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleExtensions.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleExtensions.cs
@@ -4,9 +4,7 @@
 // Created by: Alex Yakunin
 // Created:    2008.05.31
 
-using System;
 using System.Collections;
-using System.Collections.Generic;
 using Xtensive.Collections;
 using Xtensive.Core;
 
diff --git a/Orm/Xtensive.Orm/Tuples/TupleFieldState.cs b/Orm/Xtensive.Orm/Tuples/TupleFieldState.cs
index 2839d9ef42..c0ba26f11b 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleFieldState.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleFieldState.cs
@@ -4,7 +4,6 @@
 // Created by: Nick Svetlov
 // Created:    2007.06.18
 
-using System;
 
 namespace Xtensive.Tuples
 {
diff --git a/Orm/Xtensive.Orm/Tuples/TupleFieldStateExtensions.cs b/Orm/Xtensive.Orm/Tuples/TupleFieldStateExtensions.cs
index 43c5a3c1da..9be60805b7 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleFieldStateExtensions.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleFieldStateExtensions.cs
@@ -4,7 +4,6 @@
 // Created by: Alexis Kochetov
 // Created:    2009.09.17
 
-using System;
 using Xtensive.Tuples;
 
 using Tuple = Xtensive.Tuples.Tuple;
diff --git a/Orm/Xtensive.Orm/Tuples/TupleFormatExtensions.cs b/Orm/Xtensive.Orm/Tuples/TupleFormatExtensions.cs
index b131f5da51..8bdffd3dad 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleFormatExtensions.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleFormatExtensions.cs
@@ -4,8 +4,6 @@
 // Created by: Elena Vakhtina
 // Created:    2008.11.11
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Web;
@@ -15,7 +13,6 @@
 using Xtensive.Tuples;
 using Xtensive.Reflection;
 using Tuple = Xtensive.Tuples.Tuple;
-using System.Linq;
 
 namespace Xtensive.Tuples
 {
diff --git a/Orm/Xtensive.Orm/Tuples/TupleUpdater.cs b/Orm/Xtensive.Orm/Tuples/TupleUpdater.cs
index 201a731c8d..8a96f4d1c9 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleUpdater.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleUpdater.cs
@@ -4,7 +4,6 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.03.17
 
-using System;
 using Xtensive.Core;
 
 
diff --git a/Weaver/Xtensive.Orm.Weaver/Application/ConsoleMessageWriter.cs b/Weaver/Xtensive.Orm.Weaver/Application/ConsoleMessageWriter.cs
index a759504890..ff90381c9d 100644
--- a/Weaver/Xtensive.Orm.Weaver/Application/ConsoleMessageWriter.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Application/ConsoleMessageWriter.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
 
 namespace Xtensive.Orm.Weaver.Application
 {
diff --git a/Weaver/Xtensive.Orm.Weaver/Application/Program.cs b/Weaver/Xtensive.Orm.Weaver/Application/Program.cs
index 1132f04812..d4edd7dfdb 100644
--- a/Weaver/Xtensive.Orm.Weaver/Application/Program.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Application/Program.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
 using System.IO;
 
 namespace Xtensive.Orm.Weaver.Application
diff --git a/Weaver/Xtensive.Orm.Weaver/AssemblyChecker.cs b/Weaver/Xtensive.Orm.Weaver/AssemblyChecker.cs
index e243e54cec..70cc56ab3b 100644
--- a/Weaver/Xtensive.Orm.Weaver/AssemblyChecker.cs
+++ b/Weaver/Xtensive.Orm.Weaver/AssemblyChecker.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.09.02
 
-using System.Collections.Generic;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/AssemblyProcessor.cs b/Weaver/Xtensive.Orm.Weaver/AssemblyProcessor.cs
index 0e90415b44..eb27e75933 100644
--- a/Weaver/Xtensive.Orm.Weaver/AssemblyProcessor.cs
+++ b/Weaver/Xtensive.Orm.Weaver/AssemblyProcessor.cs
@@ -4,11 +4,8 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
-using System.Linq;
 using Mono.Cecil;
 using Xtensive.Orm.Weaver.Stages;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/AssemblyResolver.cs b/Weaver/Xtensive.Orm.Weaver/AssemblyResolver.cs
index e8fd454c69..84db08a833 100644
--- a/Weaver/Xtensive.Orm.Weaver/AssemblyResolver.cs
+++ b/Weaver/Xtensive.Orm.Weaver/AssemblyResolver.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.20
 
-using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Reflection;
 using Mono.Cecil;
diff --git a/Weaver/Xtensive.Orm.Weaver/Extensions.cs b/Weaver/Xtensive.Orm.Weaver/Extensions.cs
index 78d2c8f3fc..b793465206 100644
--- a/Weaver/Xtensive.Orm.Weaver/Extensions.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Extensions.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System.Collections.Generic;
-using System.Linq;
 using Mono.Cecil;
 using Mono.Collections.Generic;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/FileHelper.cs b/Weaver/Xtensive.Orm.Weaver/FileHelper.cs
index f517f30067..1067092d86 100644
--- a/Weaver/Xtensive.Orm.Weaver/FileHelper.cs
+++ b/Weaver/Xtensive.Orm.Weaver/FileHelper.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.20
 
-using System;
 using System.IO;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/MessageLogger.cs b/Weaver/Xtensive.Orm.Weaver/MessageLogger.cs
index 324d75c659..664fd9359d 100644
--- a/Weaver/Xtensive.Orm.Weaver/MessageLogger.cs
+++ b/Weaver/Xtensive.Orm.Weaver/MessageLogger.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/ProcessorConfiguration.cs b/Weaver/Xtensive.Orm.Weaver/ProcessorConfiguration.cs
index b35d7a65ed..e3f66cea72 100644
--- a/Weaver/Xtensive.Orm.Weaver/ProcessorConfiguration.cs
+++ b/Weaver/Xtensive.Orm.Weaver/ProcessorConfiguration.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Collections.Generic;
 
 namespace Xtensive.Orm.Weaver
 {
diff --git a/Weaver/Xtensive.Orm.Weaver/ProcessorContext.cs b/Weaver/Xtensive.Orm.Weaver/ProcessorContext.cs
index de29113c61..4d765aa675 100644
--- a/Weaver/Xtensive.Orm.Weaver/ProcessorContext.cs
+++ b/Weaver/Xtensive.Orm.Weaver/ProcessorContext.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Collections.Generic;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/ProcessorMessage.cs b/Weaver/Xtensive.Orm.Weaver/ProcessorMessage.cs
index ea8b82cb8e..2ca14acda4 100644
--- a/Weaver/Xtensive.Orm.Weaver/ProcessorMessage.cs
+++ b/Weaver/Xtensive.Orm.Weaver/ProcessorMessage.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
 using System.Text;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/ProcessorStageAttribute.cs b/Weaver/Xtensive.Orm.Weaver/ProcessorStageAttribute.cs
index c0112b7a0c..f8dab199e2 100644
--- a/Weaver/Xtensive.Orm.Weaver/ProcessorStageAttribute.cs
+++ b/Weaver/Xtensive.Orm.Weaver/ProcessorStageAttribute.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.12.25
 
-using System;
 
 namespace Xtensive.Orm.Weaver
 {
diff --git a/Weaver/Xtensive.Orm.Weaver/PropertyInfo.cs b/Weaver/Xtensive.Orm.Weaver/PropertyInfo.cs
index 0571aa18b8..9af23f40f3 100644
--- a/Weaver/Xtensive.Orm.Weaver/PropertyInfo.cs
+++ b/Weaver/Xtensive.Orm.Weaver/PropertyInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.26
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Mono.Cecil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/ReferenceRegistry.cs b/Weaver/Xtensive.Orm.Weaver/ReferenceRegistry.cs
index a6d48a20b6..d5a848aa60 100644
--- a/Weaver/Xtensive.Orm.Weaver/ReferenceRegistry.cs
+++ b/Weaver/Xtensive.Orm.Weaver/ReferenceRegistry.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.20
 
-using System.Collections.Generic;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/StageFailedException.cs b/Weaver/Xtensive.Orm.Weaver/StageFailedException.cs
index 3f778bf555..ec4ab65a03 100644
--- a/Weaver/Xtensive.Orm.Weaver/StageFailedException.cs
+++ b/Weaver/Xtensive.Orm.Weaver/StageFailedException.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 
 namespace Xtensive.Orm.Weaver
 {
diff --git a/Weaver/Xtensive.Orm.Weaver/Stages/FindPersistentTypesStage.cs b/Weaver/Xtensive.Orm.Weaver/Stages/FindPersistentTypesStage.cs
index 0d6e04d005..cf227bf9f7 100644
--- a/Weaver/Xtensive.Orm.Weaver/Stages/FindPersistentTypesStage.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Stages/FindPersistentTypesStage.cs
@@ -4,10 +4,7 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver.Stages
diff --git a/Weaver/Xtensive.Orm.Weaver/Stages/ImportReferencesStage.cs b/Weaver/Xtensive.Orm.Weaver/Stages/ImportReferencesStage.cs
index c2f7b1b611..1189945043 100644
--- a/Weaver/Xtensive.Orm.Weaver/Stages/ImportReferencesStage.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Stages/ImportReferencesStage.cs
@@ -4,9 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.20
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver.Stages
diff --git a/Weaver/Xtensive.Orm.Weaver/Stages/ModifyPersistentTypesStage.cs b/Weaver/Xtensive.Orm.Weaver/Stages/ModifyPersistentTypesStage.cs
index 5f8e0c016b..50f14e8623 100644
--- a/Weaver/Xtensive.Orm.Weaver/Stages/ModifyPersistentTypesStage.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Stages/ModifyPersistentTypesStage.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System.Linq;
 using Mono.Cecil;
 using Xtensive.Orm.Weaver.Tasks;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/Tasks/AddAttributeTask.cs b/Weaver/Xtensive.Orm.Weaver/Tasks/AddAttributeTask.cs
index 2848631200..b5c31b86ca 100644
--- a/Weaver/Xtensive.Orm.Weaver/Tasks/AddAttributeTask.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Tasks/AddAttributeTask.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver.Tasks
diff --git a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFactoryTask.cs b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFactoryTask.cs
index 5ec71ea2f8..1d9bad9e39 100644
--- a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFactoryTask.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFactoryTask.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Linq;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFieldAccessorTask.cs b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFieldAccessorTask.cs
index 006a761d90..b712d675c7 100644
--- a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFieldAccessorTask.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementFieldAccessorTask.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Collections.Generic;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementInitializablePatternTask.cs b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementInitializablePatternTask.cs
index 0c09c43994..cdb48908c5 100644
--- a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementInitializablePatternTask.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementInitializablePatternTask.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
-using System.Linq;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementKeySetterTask.cs b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementKeySetterTask.cs
index ae343de3a2..8571359572 100644
--- a/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementKeySetterTask.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Tasks/ImplementKeySetterTask.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.19
 
-using System;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/Tasks/RemoveBackingFieldTask.cs b/Weaver/Xtensive.Orm.Weaver/Tasks/RemoveBackingFieldTask.cs
index 19b8d9aff6..6018effec9 100644
--- a/Weaver/Xtensive.Orm.Weaver/Tasks/RemoveBackingFieldTask.cs
+++ b/Weaver/Xtensive.Orm.Weaver/Tasks/RemoveBackingFieldTask.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/TypeIdentity.cs b/Weaver/Xtensive.Orm.Weaver/TypeIdentity.cs
index 4561fc97fb..96927b9c90 100644
--- a/Weaver/Xtensive.Orm.Weaver/TypeIdentity.cs
+++ b/Weaver/Xtensive.Orm.Weaver/TypeIdentity.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
 using Mono.Cecil;
 
 namespace Xtensive.Orm.Weaver
diff --git a/Weaver/Xtensive.Orm.Weaver/TypeInfo.cs b/Weaver/Xtensive.Orm.Weaver/TypeInfo.cs
index 1f427bef1e..eb2967d811 100644
--- a/Weaver/Xtensive.Orm.Weaver/TypeInfo.cs
+++ b/Weaver/Xtensive.Orm.Weaver/TypeInfo.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.21
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Mono.Cecil;
 
diff --git a/Weaver/Xtensive.Orm.Weaver/WeavingHelper.cs b/Weaver/Xtensive.Orm.Weaver/WeavingHelper.cs
index 1c241ac01a..ea76103f40 100644
--- a/Weaver/Xtensive.Orm.Weaver/WeavingHelper.cs
+++ b/Weaver/Xtensive.Orm.Weaver/WeavingHelper.cs
@@ -4,8 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.20
 
-using System;
-using System.Collections.Generic;
 using System.Text;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
diff --git a/Weaver/Xtensive.Orm.Weaver/WellKnown.cs b/Weaver/Xtensive.Orm.Weaver/WellKnown.cs
index a363ae729c..c64fe12d73 100644
--- a/Weaver/Xtensive.Orm.Weaver/WellKnown.cs
+++ b/Weaver/Xtensive.Orm.Weaver/WellKnown.cs
@@ -4,7 +4,6 @@
 // Created by: Denis Krjuchkov
 // Created:    2013.08.20
 
-using System;
 using System.Collections.ObjectModel;
 
 namespace Xtensive.Orm.Weaver