Linq translator improvements

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Linq/ExpressionEvaluator.cs

@@ -102,7 +102,7 @@ private static bool CanEvaluateExpression(Expression expression)
           return !WellKnownInterfaces.Queryable.IsAssignableFrom(ma.Type);
         }
 
-        if (ma.Expression.Type.IsNullable() && ma.Member.Name == "Value") {
+        if (ma.Expression.Type.IsNullable() && ma.Member.Name.Equals("Value", StringComparison.Ordinal)) {
           return false;
         }
 

Orm/Xtensive.Orm/Orm/Linq/Expressions/Visitors/ExtendedExpressionReplacer.cs

@@ -120,8 +120,8 @@ protected override Expression VisitColumnExpression(ColumnExpression expression)
     protected override Expression VisitConstructorExpression(ConstructorExpression expression)
     {
       var arguments = new List<Expression>();
-      var bindings = new Dictionary<MemberInfo, Expression>();
-      var nativeBindings = new Dictionary<MemberInfo, Expression>();
+      var bindings = new Dictionary<MemberInfo, Expression>(expression.Bindings.Count);
+      var nativeBindings = new Dictionary<MemberInfo, Expression>(expression.NativeBindings.Count);
       bool recreate = false;
       foreach (var argument in expression.ConstructorArguments) {
         var result = Visit(argument);

Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs

@@ -1572,8 +1572,13 @@ private Expression VisitSetOperations(Expression outerSource, Expression innerSo
       var outerColumnList = outerItemProjector.GetColumns(ColumnExtractionModes.Distinct);
       var innerColumnList = innerItemProjector.GetColumns(ColumnExtractionModes.Distinct);
       if (!outerColumnList.Except(innerColumnList).Any() && outerColumnList.Count == innerColumnList.Count) {
-        outerColumnList = outerColumnList.OrderBy(i => i).ToList();
-        innerColumnList = innerColumnList.OrderBy(i => i).ToList();
+        var outerColumnListCopy = outerColumnList.ToList();
+        outerColumnListCopy.Sort();
+        outerColumnList = outerColumnListCopy;
+
+        var innerColumnListCopy = innerColumnList.ToList();
+        innerColumnListCopy.Sort();
+        innerColumnList = innerColumnListCopy;
       }
 
       var outerColumns = outerColumnList.ToArray();