private static AlgebraNode NullScanIfInputIsNullScan(UnaryAlgebraNode algebraNode)
{
if (algebraNode.Input is NullScanAlgebraNode)
return CreateNullScan(algebraNode.OutputList);
return algebraNode;
}
private AlgebraNode PushOverUnary(ComputeScalarAlgebraNode node)
{
UnaryAlgebraNode inputNode = (UnaryAlgebraNode)node.Input;
node.Input = inputNode.Input;
inputNode.Input = VisitAlgebraNode(node);
return(inputNode);
}
private AlgebraNode ReturnInputIfItProducesJustOneRow(UnaryAlgebraNode node)
{
node.Input = VisitAlgebraNode(node.Input);
if (AstUtil.WillProduceAtMostOneRow(node.Input))
return node.Input;
return node;
}
private static AlgebraNode NullScanIfInputIsNullScan(UnaryAlgebraNode algebraNode)
{
if (algebraNode.Input is NullScanAlgebraNode)
{
return(CreateNullScan(algebraNode.OutputList));
}
return(algebraNode);
}
private AlgebraNode ReturnInputIfItProducesJustOneRow(UnaryAlgebraNode node)
{
node.Input = VisitAlgebraNode(node.Input);
if (AstUtil.WillProduceAtMostOneRow(node.Input))
{
return(node.Input);
}
return(node);
}
private AlgebraNode PullFilterUp(UnaryAlgebraNode unaryAlgebraNode)
{
unaryAlgebraNode.Input = VisitAlgebraNode(unaryAlgebraNode.Input);
FilterAlgebraNode filterAlgebraNode = unaryAlgebraNode.Input as FilterAlgebraNode;
if (filterAlgebraNode == null)
{
return unaryAlgebraNode;
}
else
{
unaryAlgebraNode.Input = filterAlgebraNode.Input;
filterAlgebraNode.Input = unaryAlgebraNode;
return filterAlgebraNode;
}
}
private AlgebraNode PullFilterUp(UnaryAlgebraNode unaryAlgebraNode)
{
unaryAlgebraNode.Input = VisitAlgebraNode(unaryAlgebraNode.Input);
FilterAlgebraNode filterAlgebraNode = unaryAlgebraNode.Input as FilterAlgebraNode;
if (filterAlgebraNode == null)
{
return(unaryAlgebraNode);
}
else
{
unaryAlgebraNode.Input = filterAlgebraNode.Input;
filterAlgebraNode.Input = unaryAlgebraNode;
return(filterAlgebraNode);
}
}
private AlgebraNode PushOverValueDefininingUnary(IEnumerable <ValueDefinition> definedValues, FilterAlgebraNode node)
{
UnaryAlgebraNode inputNode = (UnaryAlgebraNode)node.Input;
List <ExpressionNode> nonDependingAndParts = new List <ExpressionNode>();
List <ExpressionNode> dependingAndParts = new List <ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
RowBufferEntry[] rowBufferEntries = AstUtil.GetRowBufferEntryReferences(andPart);
bool dependsOnDefinedValue = false;
foreach (ValueDefinition definedValue in definedValues)
{
if (ArrayHelpers.Contains(rowBufferEntries, definedValue.Target))
{
dependsOnDefinedValue = true;
break;
}
}
if (dependsOnDefinedValue)
{
dependingAndParts.Add(andPart);
}
else
{
nonDependingAndParts.Add(andPart);
}
}
if (nonDependingAndParts.Count > 0)
{
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, dependingAndParts);
inputNode.Input = GetFilterFromAndParts(nonDependingAndParts, inputNode.Input);
if (node.Predicate == null)
{
node.Input = inputNode.Input;
inputNode.Input = VisitAlgebraNode(node);
return(inputNode);
}
}
node.Input = VisitAlgebraNode(node.Input);
return(node);
}
