private bool TryOptimizeIN(SelectASTNode selectASTNode, ReadLogicalElement input, TableDefinition tableDefinition, out CartesianProductElement result)
{
if (selectASTNode.Condition is RelOpASTNode relOpASTNode &&
relOpASTNode.RelationOperator == Compiler.Common.RelOp.In)
{
SelectASTNode innerSelectASTNode = null;
IdentifierASTNode outerIdentifierASTNode = null;
if (relOpASTNode.Right is SelectASTNode)
{
innerSelectASTNode = (SelectASTNode)relOpASTNode.Right;
if (relOpASTNode.Left is IdentifierASTNode)
{
outerIdentifierASTNode = (IdentifierASTNode)relOpASTNode.Left;
}
}
if (relOpASTNode.Right is IdentifierASTNode)
{
outerIdentifierASTNode = (IdentifierASTNode)relOpASTNode.Right;
if (relOpASTNode.Left is SelectASTNode)
{
innerSelectASTNode = (SelectASTNode)relOpASTNode.Left;
}
}
if (innerSelectASTNode != null &&
outerIdentifierASTNode != null)
{
result = new CartesianProductElement(input, GetElementForTreeNode(innerSelectASTNode) as ReadLogicalElement, GetColumnFromIdentifierNode(tableDefinition, outerIdentifierASTNode), SelectColumnsToColumns(_relationManager.GetTable(innerSelectASTNode.From.Identifier.Identifier), innerSelectASTNode.SelectColumns).First().AttributeDefinition);
return(true);
}
}
result = null;
return(false);
}
public int GetSizeOfCondition(ReadLogicalElement input, Condition condition)
{
int sizeOfRelation = input.T();
if (condition == null)
{
return(sizeOfRelation);
}
if (condition is AndCondition andCondition)
{
return(sizeOfRelation * ((GetSizeOfCondition(input, andCondition.Left) / sizeOfRelation) * (GetSizeOfCondition(input, andCondition.Right) / sizeOfRelation)));
}
else if (condition is OrCondition orCondition)
{
int m1 = GetSizeOfCondition(input, orCondition.Left);
int m2 = GetSizeOfCondition(input, orCondition.Right);
return(sizeOfRelation * (1 - ((1 - (m1 / sizeOfRelation)) * ((m2 / sizeOfRelation)))));
}
else if (condition is LeafCondition leafCondition)
{
switch (leafCondition.Operation)
{
case Compiler.Common.RelOp.Equals:
return((int)Math.Round(sizeOfRelation * ((double)1 / (double)input.V(leafCondition.Column))));
case Compiler.Common.RelOp.GreaterOrEqualThan:
case Compiler.Common.RelOp.GreaterThan:
case Compiler.Common.RelOp.LessOrEqualThan:
case Compiler.Common.RelOp.LessThan:
case Compiler.Common.RelOp.NotEquals:
return(sizeOfRelation);
}
}
return(-1);
}
public ProjectionElement(ReadLogicalElement input, List <ProjectionColumn> columns)
: base(input)
{
Columns = columns;
}
public SelectionElement(ReadLogicalElement input, Condition condition)
: base(input)
{
Condition = condition;
}
public CartesianProductElement(ReadLogicalElement left, ReadLogicalElement right, AttributeDefinition leftJoinColumn, AttributeDefinition rightJoinColumn)
: base(left, right)
{
LeftJoinColumn = leftJoinColumn;
RightJoinColumn = rightJoinColumn;
}