diff --git a/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorKind.cs b/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorKind.cs
index cfc479fc5..a7a846ff0 100644
--- a/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorKind.cs
+++ b/Orm/Xtensive.Orm/Orm/Attributes/KeyGeneratorKind.cs
@@ -9,7 +9,7 @@ namespace Xtensive.Orm
   /// <summary>
   /// Specifies key generator type to use for a particular hierarchy.
   /// </summary>
-  public enum KeyGeneratorKind
+  public enum KeyGeneratorKind : byte
   {
     /// <summary>
     /// No key generator is provided for hierarchy.
@@ -35,4 +35,4 @@ public enum KeyGeneratorKind
     /// </summary>
     Custom = 2
   }
-}
\ No newline at end of file
+}
diff --git a/Orm/Xtensive.Orm/Orm/Domain.cs b/Orm/Xtensive.Orm/Orm/Domain.cs
index b6a68acd8..fda240a5f 100644
--- a/Orm/Xtensive.Orm/Orm/Domain.cs
+++ b/Orm/Xtensive.Orm/Orm/Domain.cs
@@ -23,6 +23,7 @@
 using Xtensive.Orm.Logging;
 using Xtensive.Orm.Model;
 using Xtensive.Orm.Providers;
+using Xtensive.Orm.Rse.Providers;
 using Xtensive.Orm.Upgrade;
 using Xtensive.Sql;
 using Xtensive.Sql.Info;
@@ -134,6 +135,21 @@ public static Domain Demand()
 
     internal ConcurrentDictionary<Type, System.Linq.Expressions.MethodCallExpression> RootCallExpressionsCache { get; } = new();
 
+    /// <summary>
+    /// Caches uncompiled queries used by <see cref="PrefetchManager"/> to fetch certain entities.
+    /// </summary>
+    internal  ConcurrentDictionary<RecordSetCacheKey, CompilableProvider> EntityFetchQueryCache { get; } = new();
+
+    /// <summary>
+    /// Caches uncompiled queries used by <see cref="PrefetchManager"/> to fetch <see cref="EntitySet{TItem}"/> content.
+    /// </summary>
+    internal ConcurrentDictionary<ItemsQueryCacheKey, CompilableProvider> EntitySetFetchQueryCache { get; } = new();
+
+    /// <summary>
+    /// Caches queries that get references to entities for certain association.
+    /// </summary>
+    internal ConcurrentDictionary<AssociationInfo, (CompilableProvider, Parameter<Xtensive.Tuples.Tuple>)> RefsToEntityQueryCache { get; } = new();
+
     internal object UpgradeContextCookie { get; private set; }
 
     internal SqlConnection SingleConnection { get; private set; }
diff --git a/Orm/Xtensive.Orm/Orm/DomainBound.cs b/Orm/Xtensive.Orm/Orm/DomainBound.cs
index 221bc66f2..2215ff6ef 100644
--- a/Orm/Xtensive.Orm/Orm/DomainBound.cs
+++ b/Orm/Xtensive.Orm/Orm/DomainBound.cs
@@ -4,60 +4,47 @@
 // Created by: Dmitri Maximov
 // Created:    2007.08.10
 
-using System;
 using Xtensive.Core;
 
-using Xtensive.IoC;
-using Xtensive.Orm;
 
-namespace Xtensive.Orm
+namespace Xtensive.Orm;
+
+/// <summary>
+/// Base class for all objects that are bound to the <see cref="Domain"/> instance.
+/// </summary>
+public abstract class DomainBound: IContextBound<Domain>
 {
   /// <summary>
-  /// Base class for all objects that are bound to the <see cref="Domain"/> instance.
+  /// Gets <see cref="Domain"/> to which current instance is bound.
+  /// </summary>
+  public Domain Domain { get; internal set; }
+
+  #region IContextBound<Domain> Members
+
+  /// <inheritdoc/>
+  Domain IContextBound<Domain>.Context => Domain;
+
+  #endregion
+
+
+  // Constructors
+
+  /// <summary>
+  /// Initializes a new instance of this class.
+  /// </summary>
+  protected DomainBound()
+  {
+  }
+
+  /// <summary>
+  /// Initializes a new instance of this class.
   /// </summary>
-  public abstract class DomainBound: IContextBound<Domain>
+  /// <param name="domain"><see cref="Orm.Domain"/>, to which current instance
+  /// is bound.</param>
+  /// <exception cref="ArgumentNullException"><paramref name="domain"/> is <see langword="null" />.</exception>
+  protected DomainBound(Domain domain)
   {
-    private Domain domain;
-
-    /// <summary>
-    /// Gets <see cref="Domain"/> to which current instance is bound.
-    /// </summary>
-    public Domain Domain
-    {
-      get { return domain; }
-      internal set { domain = value; }
-    }
-
-    #region IContextBound<Domain> Members
-
-    /// <inheritdoc/>
-    Domain IContextBound<Domain>.Context
-    {
-      get { return domain; }
-    }
-
-    #endregion
-
-
-    // Constructors
-
-    /// <summary>
-    /// Initializes a new instance of this class.
-    /// </summary>
-    protected DomainBound() 
-    {
-    }
-
-    /// <summary>
-    /// Initializes a new instance of this class.
-    /// </summary>
-    /// <param name="domain"><see cref="Orm.Domain"/>, to which current instance 
-    /// is bound.</param>
-    /// <exception cref="ArgumentNullException"><paramref name="domain"/> is <see langword="null" />.</exception>
-    protected DomainBound(Domain domain)
-    {
-      ArgumentNullException.ThrowIfNull(domain);
-      this.domain = domain;
-    }
+    ArgumentNullException.ThrowIfNull(domain);
+    Domain = domain;
   }
-}
\ No newline at end of file
+}
diff --git a/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs b/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs
index 29c75b99f..b52686a65 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/EntitySetTypeState.cs
@@ -4,34 +4,16 @@
 // Created by: Alexander Nikolaev
 // Created:    2009.08.04
 
-using System;
-using Xtensive.Tuples;
-using Xtensive.Orm.Providers;
 using Xtensive.Orm.Rse.Providers;
 using Tuple = Xtensive.Tuples.Tuple;
 using Xtensive.Tuples.Transform;
-using Xtensive.Orm.Rse;
 
-namespace Xtensive.Orm.Internals
-{
-  [Serializable]
-  internal sealed class EntitySetTypeState
-  {
-    public readonly ExecutableProvider SeekProvider;
+namespace Xtensive.Orm.Internals;
 
-    public readonly MapTransform SeekTransform;
-
-    public readonly Func<Tuple, Entity> ItemCtor;
-
-    public readonly Func<QueryEndpoint,long> ItemCountQuery;
-
-    public EntitySetTypeState(ExecutableProvider seekProvider, MapTransform seekTransform,
-      Func<Tuple, Entity> itemCtor, Func<QueryEndpoint, long> itemCountQuery)
-    {
-      SeekProvider = seekProvider;
-      SeekTransform = seekTransform;
-      ItemCtor = itemCtor;
-      ItemCountQuery = itemCountQuery;
-    }
-  }
-}
\ No newline at end of file
+[Serializable]
+internal record EntitySetTypeState(
+  ExecutableProvider SeekProvider,
+  MapTransform SeekTransform,
+  Func<Tuple, Entity> ItemCtor,
+  Func<QueryEndpoint, long> ItemCountQuery
+);
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityGroupTask.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntityGroupTask.cs
index b2d4e33ab..45fa7a7d0 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.Collections;
 using Xtensive.Core;
 using Xtensive.Orm.Model;
@@ -33,11 +30,17 @@ public override bool Equals(object obj) =>
 
     // Constructors
 
-    public RecordSetCacheKey(IReadOnlyList<ColNum> columnIndexes, TypeInfo type, int cachedHashCode)
+    public RecordSetCacheKey(IReadOnlyList<ColNum> columnIndexes, TypeInfo type)
     {
       ColumnIndexes = columnIndexes;
       Type = type;
-      this.cachedHashCode = cachedHashCode;
+
+      HashCode hashCode = new();
+      foreach (var columnIndex in columnIndexes) {
+        hashCode.Add(columnIndex);
+      }
+      hashCode.Add(type);
+      cachedHashCode = hashCode.ToHashCode();
     }
   }
 
@@ -125,7 +128,7 @@ private QueryTask CreateQueryTask(List<Tuple> currentKeySet)
       var parameterContext = new ParameterContext();
       parameterContext.SetValue(includeParameter, currentKeySet);
       var session = manager.Owner.Session;
-      Provider = session.StorageNode.EntityFetchQueryCache.GetOrAdd(cacheKey, CreateRecordSet);
+      Provider = manager.Owner.Session.Domain.EntityFetchQueryCache.GetOrAdd(cacheKey, static k => CreateRecordSet(k));
       if (session.Domain.TagsEnabled && session.Tags != null) {
         foreach (var tag in session.Tags) {
           Provider = new TagProvider(Provider, tag);
@@ -192,13 +195,7 @@ public EntityGroupTask(TypeInfo type, IReadOnlyList<ColNum> columnIndexes, Prefe
 
       this.type = type;
       this.manager = manager;
-      var cachedHashCode = 0;
-      foreach (var columnIndex in columnIndexes) {
-        cachedHashCode = unchecked (379 * cachedHashCode + columnIndex);
-      }
-
-      cachedHashCode ^= type.GetHashCode();
-      cacheKey = new RecordSetCacheKey(columnIndexes, type, cachedHashCode);
+      cacheKey = new RecordSetCacheKey(columnIndexes, type);
     }
   }
 }
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs
index dc4739a6d..88046ed36 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs
@@ -4,11 +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;
 using Xtensive.Orm.Linq;
 using Xtensive.Orm.Model;
@@ -173,7 +168,7 @@ private QueryTask CreateQueryTask()
 
       var session = manager.Owner.Session;
       var scope = new CompiledQueryProcessingScope(null, null, parameterContext, false);
-      QueryProvider = session.StorageNode.EntitySetFetchQueryCache.GetOrAdd(cacheKey, CreateRecordSetLoadingItems);
+      QueryProvider = session.Domain.EntitySetFetchQueryCache.GetOrAdd(cacheKey, static k => CreateRecordSetLoadingItems(k));
       if (session.Domain.TagsEnabled && session.Tags != null) {
         foreach (var tag in session.Tags) {
           QueryProvider = new TagProvider(QueryProvider, tag);
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs
index b9d6f2f41..a18c9b15a 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchHelper.cs
@@ -75,14 +75,9 @@ public static bool AddColumns(IEnumerable<ColumnInfo> candidateColumns,
       return result;
     }
 
-    public static List<ColNum> GetColumnsToBeLoaded(SortedDictionary<ColNum, ColumnInfo> userColumnIndexes,
-      TypeInfo type)
-    {
-      var result = new List<ColNum>(userColumnIndexes.Count);
-      result.AddRange(type.Indexes.PrimaryIndex.ColumnIndexMap.System);
-      result.AddRange(userColumnIndexes.Where(pair => !pair.Value.IsPrimaryKey
-        && !pair.Value.IsSystem).Select(pair => pair.Key));
-      return result;
-    }
+    public static IReadOnlyList<ColNum> GetColumnsToBeLoaded(SortedDictionary<ColNum, ColumnInfo> userColumnIndexes, TypeInfo type) =>
+      type.Indexes.PrimaryIndex.ColumnIndexMap.System
+        .Concat(userColumnIndexes.Where(pair => !pair.Value.IsPrimaryKey && !pair.Value.IsSystem).Select(pair => pair.Key))
+        .ToArray();
   }
-}
\ No newline at end of file
+}
diff --git a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs
index cffb6bdc3..ae0f70970 100644
--- a/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs
+++ b/Orm/Xtensive.Orm/Orm/Internals/Prefetch/PrefetchManager.cs
@@ -49,25 +49,11 @@ public RootContainerCacheKey(TypeInfo type, IEnumerable<PrefetchFieldDescriptor>
       }
     }
 
-    private class RootContainerCacheEntry
-    {
-      public readonly RootContainerCacheKey Key;
-
-      public readonly SortedDictionary<ColNum, ColumnInfo> Columns;
-
-      public readonly IReadOnlyList<ColNum> ColumnsToBeLoaded;
-
-
-      // Constructors
-
-      public RootContainerCacheEntry(in RootContainerCacheKey key, SortedDictionary<ColNum, ColumnInfo> columns,
-        IReadOnlyList<ColNum> columnsToBeLoaded)
-      {
-        Key = key;
-        Columns = columns;
-        ColumnsToBeLoaded = columnsToBeLoaded;
-      }
-    }
+    private record struct RootContainerCacheEntry(
+      RootContainerCacheKey Key,
+      SortedDictionary<ColNum, ColumnInfo> Columns,
+      IReadOnlyList<ColNum> ColumnsToBeLoaded
+    );
 
     #endregion
 
@@ -257,7 +243,7 @@ public void GetCachedColumnIndexes(TypeInfo type,
     {
       var cacheKey = new RootContainerCacheKey(type, descriptors);
       var cacheEntry = columnsCache[cacheKey, true];
-      if (cacheEntry == null) {
+      if (cacheEntry == default) {
         columns = PrefetchHelper.GetColumns(ExtractColumns(descriptors),type);
         columnsToBeLoaded = PrefetchHelper.GetColumnsToBeLoaded(columns, type);
         cacheEntry = new RootContainerCacheEntry(cacheKey, columns, columnsToBeLoaded);
diff --git a/Orm/Xtensive.Orm/Orm/Model/InheritanceSchema.cs b/Orm/Xtensive.Orm/Orm/Model/InheritanceSchema.cs
index 001e866d0..b63e96e77 100644
--- a/Orm/Xtensive.Orm/Orm/Model/InheritanceSchema.cs
+++ b/Orm/Xtensive.Orm/Orm/Model/InheritanceSchema.cs
@@ -10,7 +10,7 @@ namespace Xtensive.Orm.Model
   /// Enumerates all supported 'class to tables mapping' schemes.
   /// </summary>
   /// <remarks>See M.Fowler - "Patterns of Enterprise Application Architecture".</remarks>
-  public enum InheritanceSchema
+  public enum InheritanceSchema : byte
   {
     /// <summary>
     /// Is equal to <see cref="ClassTable"/>.
@@ -30,4 +30,4 @@ public enum InheritanceSchema
     /// </summary>
     ConcreteTable = 2
   }
-}
\ No newline at end of file
+}
diff --git a/Orm/Xtensive.Orm/Orm/PersistenceState.cs b/Orm/Xtensive.Orm/Orm/PersistenceState.cs
index 2ae6b2b69..7bda3240a 100644
--- a/Orm/Xtensive.Orm/Orm/PersistenceState.cs
+++ b/Orm/Xtensive.Orm/Orm/PersistenceState.cs
@@ -9,7 +9,7 @@ namespace Xtensive.Orm
   /// <summary>
   /// Defines possible persistence states of the entities.
   /// </summary>
-  public enum PersistenceState
+  public enum PersistenceState : byte
   {
     /// <summary>
     /// The entity is synchronized with the database (there are no unsaved changes).
@@ -28,4 +28,4 @@ public enum PersistenceState
     /// </summary>
     Removed = 3,
   }
-}
\ No newline at end of file
+}
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs
index 5ed8b074e..a3db2deaf 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.References.cs
@@ -29,7 +29,7 @@ public virtual IEnumerable<ReferenceInfo> GetReferencesTo(Entity target, Associa
     {
       if (association.IsPaired)
         return FindReferences(target, association, true);
-      var (recordSet, parameter) = Session.StorageNode.RefsToEntityQueryCache .GetOrAdd(association, BuildReferencingQuery);
+      var (recordSet, parameter) = Session.Domain.RefsToEntityQueryCache.GetOrAdd(association, static k => BuildReferencingQuery(k));
       var parameterContext = new ParameterContext();
       parameterContext.SetValue(parameter, target.Key.Value);
       ExecutableProvider executableProvider = Session.Compile(recordSet);
diff --git a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs
index b6ac66b3b..a10181f98 100644
--- a/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs
+++ b/Orm/Xtensive.Orm/Orm/Providers/SessionHandler.cs
@@ -22,7 +22,7 @@ public abstract partial class SessionHandler : IDisposable, IAsyncDisposable
     /// <summary>
     /// Gets <see cref="HandlerAccessor"/>.
     /// </summary>
-    protected HandlerAccessor Handlers { get; private set; }
+    protected HandlerAccessor Handlers => Session.Handlers;
 
     /// <summary>
     /// Gets the current <see cref="Session"/>.
@@ -117,7 +117,6 @@ public virtual void Dispose()
     protected SessionHandler(Session session)
     {
       Session = session;
-      Handlers = session.Handlers;
     }
   }
-}
\ No newline at end of file
+}
diff --git a/Orm/Xtensive.Orm/Orm/Session.cs b/Orm/Xtensive.Orm/Orm/Session.cs
index 298c5b93f..200de0379 100644
--- a/Orm/Xtensive.Orm/Orm/Session.cs
+++ b/Orm/Xtensive.Orm/Orm/Session.cs
@@ -235,7 +235,7 @@ public static Func<Session> Resolver
 
     internal SessionHandler Handler { get; set; }
 
-    internal HandlerAccessor Handlers { get; private set; }
+    internal HandlerAccessor Handlers => Domain.Handlers;
 
     internal SyncManager PairSyncManager { get; }
 
@@ -546,7 +546,6 @@ internal Session(Domain domain, StorageNode selectedStorageNode, SessionConfigur
       storageNode = selectedStorageNode;
 
       // Handlers
-      Handlers = domain.Handlers;
       Handler = CreateSessionHandler();
 
       // Caches, registry
diff --git a/Orm/Xtensive.Orm/Orm/StorageNode.cs b/Orm/Xtensive.Orm/Orm/StorageNode.cs
index fc130bceb..3f15317bc 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;
@@ -31,7 +27,7 @@ public sealed class StorageNode : ISessionSource
     /// <summary>
     /// Gets node identifier.
     /// </summary>
-    public string Id { get { return Configuration.NodeId; } }
+    public string Id => Configuration.NodeId;
 
     /// <summary>
     /// Gets node configuration.
@@ -53,25 +49,12 @@ public sealed class StorageNode : ISessionSource
     /// </summary>
     internal ConcurrentDictionary<(TypeInfo, LockMode, LockBehavior), ExecutableProvider> EntityLockProviderCache { get; } = new();
 
-    /// <summary>
-    /// Caches uncompiled queries used by <see cref="PrefetchManager"/> to fetch certain entities.
-    /// </summary>
-    internal ConcurrentDictionary<RecordSetCacheKey, CompilableProvider> EntityFetchQueryCache { get; } = new();
-
-    /// <summary>
-    /// Caches uncompiled queries used by <see cref="PrefetchManager"/> to fetch <see cref="EntitySet{TItem}"/> content.
-    /// </summary>
-    internal ConcurrentDictionary<ItemsQueryCacheKey, CompilableProvider> EntitySetFetchQueryCache { get; } = new();
 
     /// <summary>
     /// Caches certain info about EntitySet fields, e.g. queries to fetch current count or items.
     /// </summary>
     internal ConcurrentDictionary<Xtensive.Orm.Model.FieldInfo, EntitySetTypeState> EntitySetTypeStateCache { get; } = new();
 
-    /// <summary>
-    /// Caches queries that get references to entities for certain association.
-    /// </summary>
-    internal ConcurrentDictionary<AssociationInfo, (CompilableProvider, Parameter<Xtensive.Tuples.Tuple>)> RefsToEntityQueryCache { get; } = new();
     internal ConcurrentDictionary<SequenceInfo, CachingSequence> KeySequencesCache { get; } = new();
     internal ConcurrentDictionary<PersistRequestBuilderTask, IReadOnlyList<PreparedPersistRequest>> PersistRequestCache { get; } = new();
 
diff --git a/Orm/Xtensive.Orm/Orm/TypeReference.cs b/Orm/Xtensive.Orm/Orm/TypeReference.cs
index 93faa6d0f..f6dc6be4d 100644
--- a/Orm/Xtensive.Orm/Orm/TypeReference.cs
+++ b/Orm/Xtensive.Orm/Orm/TypeReference.cs
@@ -4,40 +4,12 @@
 // Created by: Dmitri Maximov
 // Created:    2009.10.09
 
-using System;
-
 using Xtensive.Orm.Model;
 
-namespace Xtensive.Orm
-{
-  /// <summary>
-  /// Reference to <see cref="TypeInfo"/> with the specified degree of accuracy.
-  /// </summary>
-  [Serializable]
-  public readonly struct TypeReference
-  {
-    /// <summary>
-    /// Gets the referenced type.
-    /// </summary>
-    public TypeInfo Type { get; }
-
-    /// <summary>
-    /// Gets the type reference accuracy.
-    /// </summary>
-    public TypeReferenceAccuracy Accuracy { get; }
-
-
-    // Constructor
+namespace Xtensive.Orm;
 
-    /// <summary>
-    /// Initializes a new instance of this class.
-    /// </summary>
-    /// <param name="type">The referenced type.</param>
-    /// <param name="accuracy">The type reference accuracy.</param>
-    public TypeReference(TypeInfo type, TypeReferenceAccuracy accuracy)
-    {
-      Type = type;
-      Accuracy = accuracy;
-    }
-  }
-}
+/// <summary>
+/// Reference to <see cref="TypeInfo"/> with the specified degree of accuracy.
+/// </summary>
+[Serializable]
+public record struct TypeReference(TypeInfo Type, TypeReferenceAccuracy Accuracy);
diff --git a/Orm/Xtensive.Orm/Orm/TypeReferenceAccuracy.cs b/Orm/Xtensive.Orm/Orm/TypeReferenceAccuracy.cs
index 01b3c34fe..ba2175e66 100644
--- a/Orm/Xtensive.Orm/Orm/TypeReferenceAccuracy.cs
+++ b/Orm/Xtensive.Orm/Orm/TypeReferenceAccuracy.cs
@@ -9,7 +9,7 @@ namespace Xtensive.Orm
   /// <summary>
   /// Describes type reference accuracy.
   /// </summary>
-  public enum TypeReferenceAccuracy
+  public enum TypeReferenceAccuracy : byte
   {
     /// <summary>
     /// Referenced type is limited to the entire hierarchy.
@@ -26,4 +26,4 @@ public enum TypeReferenceAccuracy
     /// </summary>
     ExactType = 2,
   }
-}
\ No newline at end of file
+}