Implement Lazy 2-level multi-row INSERT batches: sizes 16, 256

Author: SergeiPavlov

Orm/Xtensive.Orm/Orm/Providers/Interfaces/IPersistDescriptor.cs

@@ -1,16 +1,19 @@
-// Copyright (C) 2012 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// 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.
 // Created by: Denis Krjuchkov
 // Created:    2012.03.22
 
+using System;
+
 namespace Xtensive.Orm.Providers
 {
   public interface IPersistDescriptor
   {
     PersistRequest StoreRequest { get; }
 
-    PersistRequest BatchStoreRequest { get; }
+    Lazy<PersistRequest> LazyLevel1BatchStoreRequest { get; }
+    Lazy<PersistRequest> LazyLevel2BatchStoreRequest { get; }
 
     PersistRequest ClearRequest { get; }
   }

Orm/Xtensive.Orm/Orm/Providers/SqlSessionHandler.IProviderExecutor.cs

@@ -85,15 +85,21 @@ private void Execute(ParameterContext parameterContext)
 
     private void Store(IPersistDescriptor descriptor, IEnumerable<Tuple> tuples)
     {
-      if (descriptor.BatchStoreRequest != null) {
-        var parametersInBatchStoreRequest = descriptor.BatchStoreRequest.ParameterBindings.Count;
-        foreach (var chunk in tuples.Chunk(parametersInBatchStoreRequest)) {
-          if (chunk.Length == parametersInBatchStoreRequest) {
-            commandProcessor.RegisterTask(new SqlPersistTask(descriptor.BatchStoreRequest, chunk));
+      if (descriptor.LazyLevel1BatchStoreRequest != null && descriptor.LazyLevel2BatchStoreRequest != null) {
+        foreach (var level2Chunk in tuples.Chunk(WellKnown.MultiRowInsertLevel2BatchSize)) {
+          if (level2Chunk.Length == WellKnown.MultiRowInsertLevel2BatchSize) {
+            commandProcessor.RegisterTask(new SqlPersistTask(descriptor.LazyLevel2BatchStoreRequest.Value, level2Chunk));
           }
           else {
-            foreach (var tuple in chunk) {
-              commandProcessor.RegisterTask(new SqlPersistTask(descriptor.StoreRequest, tuple));
+            foreach (var level1Chunk in level2Chunk.Chunk(WellKnown.MultiRowInsertLevel1BatchSize)) {
+              if (level1Chunk.Length == WellKnown.MultiRowInsertLevel1BatchSize) {
+                commandProcessor.RegisterTask(new SqlPersistTask(descriptor.LazyLevel1BatchStoreRequest.Value, level1Chunk));
+              }
+              else {
+                foreach (var tuple in level1Chunk) {
+                  commandProcessor.RegisterTask(new SqlPersistTask(descriptor.StoreRequest, tuple));
+                }
+              }
             }
           }
         }

Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableDescriptor.cs

@@ -1,9 +1,10 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2003-2022 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Denis Krjuchkov
 // Created:    2009.11.12
 
+using System;
 using Xtensive.Core;
 
 using Xtensive.Tuples;
@@ -40,7 +41,12 @@ public sealed class TemporaryTableDescriptor : IPersistDescriptor
     /// <summary>
     /// Gets or sets the persist request used to store batched data in temporary table.
     /// </summary>
-    public PersistRequest BatchStoreRequest { get; set; }
+    public Lazy<PersistRequest> LazyLevel1BatchStoreRequest { get; set; }
+
+    /// <summary>
+    /// Gets or sets the persist request used to store batched data in temporary table.
+    /// </summary>
+    public Lazy<PersistRequest> LazyLevel2BatchStoreRequest { get; set; }
 
     /// <summary>
     /// Gets or sets the persist request used to store data in temporary table.

Orm/Xtensive.Orm/Orm/Providers/TemporaryTables/TemporaryTableManager.cs

@@ -84,9 +84,6 @@ public TemporaryTableDescriptor BuildDescriptor(ModelMapping modelMapping, strin
 
       // insert statements
 
-      var batchStoreRequestBindings = new List<PersistParameterBinding>();
-      var numberOfRecordsInInsert = (int)Math.Sqrt(Handlers.Domain.Configuration.MaxNumberOfConditions);
-      var batchInsertStatement = MakeUpInsertQuery(tableRef, typeMappings, batchStoreRequestBindings, hasColumns, numberOfRecordsInInsert);
 
       var storeRequestBindings = new List<PersistParameterBinding>();
       var insertStatement = MakeUpInsertQuery(tableRef, typeMappings, storeRequestBindings, hasColumns, 1);
@@ -96,16 +93,24 @@ public TemporaryTableDescriptor BuildDescriptor(ModelMapping modelMapping, strin
         QueryStatement = queryStatement,
         CreateStatement = driver.Compile(SqlDdl.Create(table)).GetCommandText(),
         DropStatement = driver.Compile(SqlDdl.Drop(table)).GetCommandText(),
-        BatchStoreRequest = new PersistRequest(driver, batchInsertStatement, batchStoreRequestBindings),
+        LazyLevel1BatchStoreRequest = CreateLazyPersistRequest(WellKnown.MultiRowInsertLevel1BatchSize),
+        LazyLevel2BatchStoreRequest = CreateLazyPersistRequest(WellKnown.MultiRowInsertLevel2BatchSize),
         StoreRequest = new PersistRequest(driver, insertStatement, storeRequestBindings),
         ClearRequest = new PersistRequest(driver, Handlers.ProviderInfo.Supports(ProviderFeatures.TruncateTable) ? SqlDdl.Truncate(table) : SqlDml.Delete(tableRef), null)
       };
 
-      result.BatchStoreRequest.Prepare();
       result.StoreRequest.Prepare();
       result.ClearRequest.Prepare();
-
       return result;
+
+      Lazy<PersistRequest> CreateLazyPersistRequest(int batchSize) =>
+        new Lazy<PersistRequest>(() => {
+          var bindings = new List<PersistParameterBinding>(batchSize);
+          var level2BatchInsertStatement = MakeUpInsertQuery(tableRef, typeMappings, bindings, hasColumns, batchSize);
+          var persistRequest = new PersistRequest(driver, level2BatchInsertStatement, bindings);
+          persistRequest.Prepare();
+          return persistRequest;
+        });
     }
 
     /// <summary>

Orm/Xtensive.Orm/Orm/Upgrade/Internals/Metadata/MetadataWriter.cs

@@ -28,7 +28,8 @@ internal sealed class MetadataWriter
     private sealed class Descriptor : IPersistDescriptor
     {
       public PersistRequest StoreRequest { get; set; }
-      public PersistRequest BatchStoreRequest { get; }
+      public Lazy<PersistRequest> LazyLevel1BatchStoreRequest { get; }
+      public Lazy<PersistRequest> LazyLevel2BatchStoreRequest { get; }
       public PersistRequest ClearRequest { get; set; }
     }
 

Orm/Xtensive.Orm/Orm/WellKnown.cs

@@ -89,6 +89,10 @@ public static partial class WellKnown
     /// </summary>
     public const int MaxGenericKeyLength = 4;
 
+    public const int MultiRowInsertLevel1BatchSize = 16;
+
+    public const int MultiRowInsertLevel2BatchSize = 256;
+
     /// <summary>
     /// Maximum number of cached keys in <see cref="EntitySetState"/>.
     /// </summary>