Apply corrections of decimal aggregate columns for postgre

+ small code imrovements of base DomainHandler

Author: alex-kulakov

Orm/Xtensive.Orm.PostgreSql/Orm.Providers.PostgreSql/DomainHandler.cs

@@ -9,6 +9,7 @@
 using System.Linq;
 using Xtensive.Core;
 using Xtensive.Orm.Rse.Compilation;
+using Xtensive.Orm.Rse.Transformation;
 
 namespace Xtensive.Orm.Providers.PostgreSql
 {
@@ -21,6 +22,12 @@ public class DomainHandler : Providers.DomainHandler
     protected override ICompiler CreateCompiler(CompilerConfiguration configuration) =>
       new SqlCompiler(Handlers, configuration);
 
+    protected override IPreCompiler CreatePreCompiler(CompilerConfiguration configuration)
+    {
+      var decimalAggregateCorrector = new AggregateOverDecimalColumnCorrector(Handlers.Domain.Model);
+      return new CompositePreCompiler(decimalAggregateCorrector, base.CreatePreCompiler(configuration));
+    }
+
     /// <inheritdoc/>
     protected override IEnumerable<Type> GetProviderCompilerContainers()
     {

Orm/Xtensive.Orm/Orm/Providers/DomainHandler.cs

@@ -168,31 +168,29 @@ private void BuildQueryPreprocessors()
     {
       var unordered = Domain.Services.GetAll<IQueryPreprocessor>();
       var ordered = unordered.SortTopologically((first, second) => second.IsDependentOn(first));
-      if (ordered==null)
-        throw new InvalidOperationException(Strings.ExCyclicDependencyInQueryPreprocessorGraphIsDetected);
-      QueryPreprocessors = ordered;
+      QueryPreprocessors = ordered ?? throw new InvalidOperationException(Strings.ExCyclicDependencyInQueryPreprocessorGraphIsDetected);
     }
 
     private static ProviderOrderingDescriptor ResolveOrderingDescriptor(CompilableProvider provider)
     {
-      bool isOrderSensitive = provider.Type==ProviderType.Skip 
-        || provider.Type == ProviderType.Take
-        || provider.Type == ProviderType.Seek
-        || provider.Type == ProviderType.Paging
-        || provider.Type == ProviderType.RowNumber;
-      bool preservesOrder = provider.Type==ProviderType.Take
-        || provider.Type == ProviderType.Skip
-        || provider.Type == ProviderType.Seek
-        || provider.Type == ProviderType.RowNumber
-        || provider.Type == ProviderType.Paging
-        || provider.Type == ProviderType.Distinct
-        || provider.Type == ProviderType.Alias;
-      bool isOrderBreaker = provider.Type == ProviderType.Except
-        || provider.Type == ProviderType.Intersect
-        || provider.Type == ProviderType.Union
-        || provider.Type == ProviderType.Concat
-        || provider.Type == ProviderType.Existence;
-      bool isSorter = provider.Type==ProviderType.Sort || provider.Type == ProviderType.Index;
+      var isOrderSensitive = provider.Type is ProviderType.Skip
+        or ProviderType.Take
+        or ProviderType.Seek
+        or ProviderType.Paging
+        or ProviderType.RowNumber;
+      var preservesOrder = provider.Type is ProviderType.Skip
+        or ProviderType.Take
+        or ProviderType.Seek
+        or ProviderType.Paging
+        or ProviderType.RowNumber
+        or ProviderType.Distinct
+        or ProviderType.Alias;
+      var isOrderBreaker = provider.Type is ProviderType.Except
+        or ProviderType.Intersect
+        or ProviderType.Union
+        or ProviderType.Concat
+        or ProviderType.Existence;
+      var isSorter = provider.Type is ProviderType.Sort or ProviderType.Index;
       return new ProviderOrderingDescriptor(isOrderSensitive, preservesOrder, isOrderBreaker, isSorter);
     }