public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// For easier handling we replace right operations by equivalent
// left operations.
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin)
{
node.SwapSides();
return VisitAlgebraNode(node);
}
// Visit children
bool semiJoinContext;
semiJoinContext = (node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin);
_semiJoinContextFlagStack.Push(semiJoinContext);
node.Left = VisitAlgebraNode(node.Left);
_semiJoinContextFlagStack.Pop();
semiJoinContext = (node.Op == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin);
_semiJoinContextFlagStack.Push(semiJoinContext);
node.Right = VisitAlgebraNode(node.Right);
_semiJoinContextFlagStack.Pop();
return node;
}
private static AlgebraNode PadLeftWithNullsOnRightSide(JoinAlgebraNode node, RowBufferCreationMode rowBufferCreationMode)
{
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = node.Left;
List <RowBufferEntry> outputList = new List <RowBufferEntry>();
outputList.AddRange(node.Left.OutputList);
List <ComputedValueDefinition> definedValues = new List <ComputedValueDefinition>();
foreach (RowBufferEntry rowBufferEntry in node.Right.OutputList)
{
ComputedValueDefinition definedValue = new ComputedValueDefinition();
if (rowBufferCreationMode == RowBufferCreationMode.KeepExisting)
{
definedValue.Target = rowBufferEntry;
}
else
{
definedValue.Target = new RowBufferEntry(rowBufferEntry.DataType);
}
definedValue.Expression = LiteralExpression.FromTypedNull(rowBufferEntry.DataType);
definedValues.Add(definedValue);
outputList.Add(definedValue.Target);
}
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
computeScalarAlgebraNode.OutputList = outputList.ToArray();
return(computeScalarAlgebraNode);
}
private AlgebraNode PushOverJoin(ComputeScalarAlgebraNode node)
{
JoinAlgebraNode joinAlgebraNode = (JoinAlgebraNode)node.Input;
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(joinAlgebraNode.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(joinAlgebraNode.Right);
List <ComputedValueDefinition> remainingValueDefinitions = new List <ComputedValueDefinition>();
List <ComputedValueDefinition> leftPushedValueDefinitions = new List <ComputedValueDefinition>();
List <ComputedValueDefinition> rightPushedValueDefinitions = new List <ComputedValueDefinition>();
bool canPushToLeftSide = joinAlgebraNode.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin &&
joinAlgebraNode.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin;
bool canPushToRightSide = joinAlgebraNode.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
joinAlgebraNode.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin;
foreach (ComputedValueDefinition valueDefinition in node.DefinedValues)
{
RowBufferEntry[] referencedValues = AstUtil.GetRowBufferEntryReferences(valueDefinition.Expression);
bool referencesProbeColumn = ArrayHelpers.Contains(referencedValues, joinAlgebraNode.ProbeBufferEntry);
if (!referencesProbeColumn && canPushToLeftSide && AstUtil.DoesNotReference(referencedValues, rightDefinedValues))
{
leftPushedValueDefinitions.Add(valueDefinition);
}
else if (!referencesProbeColumn && canPushToRightSide && AstUtil.DoesNotReference(referencedValues, leftDefinedValues))
{
rightPushedValueDefinitions.Add(valueDefinition);
}
else
{
remainingValueDefinitions.Add(valueDefinition);
}
}
if (leftPushedValueDefinitions.Count > 0)
{
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.DefinedValues = leftPushedValueDefinitions.ToArray();
computeScalarAlgebraNode.Input = joinAlgebraNode.Left;
joinAlgebraNode.Left = VisitAlgebraNode(computeScalarAlgebraNode);
}
if (rightPushedValueDefinitions.Count > 0)
{
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.DefinedValues = rightPushedValueDefinitions.ToArray();
computeScalarAlgebraNode.Input = joinAlgebraNode.Right;
joinAlgebraNode.Right = VisitAlgebraNode(computeScalarAlgebraNode);
}
if (remainingValueDefinitions.Count == 0)
{
return(joinAlgebraNode);
}
node.DefinedValues = remainingValueDefinitions.ToArray();
return(node);
}
private static AlgebraNode PadLeftWithNullsOnRightSide(JoinAlgebraNode node, RowBufferCreationMode rowBufferCreationMode)
{
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = node.Left;
List<RowBufferEntry> outputList = new List<RowBufferEntry>();
outputList.AddRange(node.Left.OutputList);
List<ComputedValueDefinition> definedValues = new List<ComputedValueDefinition>();
foreach (RowBufferEntry rowBufferEntry in node.Right.OutputList)
{
ComputedValueDefinition definedValue = new ComputedValueDefinition();
if (rowBufferCreationMode == RowBufferCreationMode.KeepExisting)
{
definedValue.Target = rowBufferEntry;
}
else
{
definedValue.Target = new RowBufferEntry(rowBufferEntry.DataType);
}
definedValue.Expression = LiteralExpression.FromTypedNull(rowBufferEntry.DataType);
definedValues.Add(definedValue);
outputList.Add(definedValue.Target);
}
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
computeScalarAlgebraNode.OutputList = outputList.ToArray();
return computeScalarAlgebraNode;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
base.VisitJoinAlgebraNode(node);
if (node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
// TODO: Check if we could represent this join condition by an hash match operator
JoinAlgebraNode leftOuterJoinNode = new JoinAlgebraNode();
leftOuterJoinNode.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
leftOuterJoinNode.Predicate = (ExpressionNode)node.Predicate.Clone();
leftOuterJoinNode.Left = (AlgebraNode) node.Left.Clone();
leftOuterJoinNode.Right = (AlgebraNode) node.Right.Clone();
leftOuterJoinNode.OutputList = ArrayHelpers.Clone(node.OutputList);
List<RowBufferEntry> swappedOutputList = new List<RowBufferEntry>();
swappedOutputList.AddRange(node.Right.OutputList);
swappedOutputList.AddRange(node.Left.OutputList);
JoinAlgebraNode leftAntiSemiJoinNode = new JoinAlgebraNode();
leftAntiSemiJoinNode.Op = JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin;
leftAntiSemiJoinNode.Predicate = (ExpressionNode) node.Predicate.Clone();
leftAntiSemiJoinNode.Left = (AlgebraNode) node.Right.Clone();
leftAntiSemiJoinNode.Right = (AlgebraNode) node.Left.Clone();
leftAntiSemiJoinNode.OutputList = swappedOutputList.ToArray();
List<ComputedValueDefinition> computeScalareDefinedValues = new List<ComputedValueDefinition>();
foreach (RowBufferEntry rowBufferEntry in node.Left.OutputList)
{
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = rowBufferEntry;
definedValue.Expression = LiteralExpression.FromTypedNull(rowBufferEntry.DataType);
computeScalareDefinedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarNode = new ComputeScalarAlgebraNode();
computeScalarNode.Input = leftAntiSemiJoinNode;
computeScalarNode.DefinedValues = computeScalareDefinedValues.ToArray();
computeScalarNode.OutputList = swappedOutputList.ToArray();
List<UnitedValueDefinition> concatDefinedValues = new List<UnitedValueDefinition>();
for (int i = 0; i < node.OutputList.Length; i++)
{
RowBufferEntry rowBufferEntry = node.OutputList[i];
UnitedValueDefinition concatDefinedValue = new UnitedValueDefinition();
concatDefinedValue.Target = rowBufferEntry;
concatDefinedValue.DependendEntries = new RowBufferEntry[] { node.OutputList[i], node.OutputList[i] };
concatDefinedValues.Add(concatDefinedValue);
}
ConcatAlgebraNode concatenationNode = new ConcatAlgebraNode();
concatenationNode.Inputs = new AlgebraNode[] {leftOuterJoinNode, computeScalarNode};
concatenationNode.DefinedValues = concatDefinedValues.ToArray();
concatenationNode.OutputList = swappedOutputList.ToArray();
return concatenationNode;
}
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Reorder
//
// A LSJ (B LOJ C) ---> (A LOJ C) LSJ B (LOJ has no join condition and C produces at most one row)
if (node.Op == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin)
{
JoinAlgebraNode rightChildJoin = node.Right as JoinAlgebraNode;
if (rightChildJoin != null &&
rightChildJoin.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
rightChildJoin.Predicate == null &&
AstUtil.WillProduceAtMostOneRow(rightChildJoin.Right))
{
node.Right = rightChildJoin.Left;
rightChildJoin.Left = node.Left;
node.Left = rightChildJoin;
return VisitAlgebraNode(node);
}
}
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// For easier handling we replace right operations by equivalent
// left operations.
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin)
{
node.SwapSides();
return(VisitAlgebraNode(node));
}
// Visit children
bool semiJoinContext;
semiJoinContext = (node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin);
_semiJoinContextFlagStack.Push(semiJoinContext);
node.Left = VisitAlgebraNode(node.Left);
_semiJoinContextFlagStack.Pop();
semiJoinContext = (node.Op == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin);
_semiJoinContextFlagStack.Push(semiJoinContext);
node.Right = VisitAlgebraNode(node.Right);
_semiJoinContextFlagStack.Pop();
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
base.VisitJoinAlgebraNode(node);
if (node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
// TODO: Check if we could represent this join condition by an hash match operator
JoinAlgebraNode leftOuterJoinNode = new JoinAlgebraNode();
leftOuterJoinNode.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
leftOuterJoinNode.Predicate = (ExpressionNode)node.Predicate.Clone();
leftOuterJoinNode.Left = (AlgebraNode)node.Left.Clone();
leftOuterJoinNode.Right = (AlgebraNode)node.Right.Clone();
leftOuterJoinNode.OutputList = ArrayHelpers.Clone(node.OutputList);
List <RowBufferEntry> swappedOutputList = new List <RowBufferEntry>();
swappedOutputList.AddRange(node.Right.OutputList);
swappedOutputList.AddRange(node.Left.OutputList);
JoinAlgebraNode leftAntiSemiJoinNode = new JoinAlgebraNode();
leftAntiSemiJoinNode.Op = JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin;
leftAntiSemiJoinNode.Predicate = (ExpressionNode)node.Predicate.Clone();
leftAntiSemiJoinNode.Left = (AlgebraNode)node.Right.Clone();
leftAntiSemiJoinNode.Right = (AlgebraNode)node.Left.Clone();
leftAntiSemiJoinNode.OutputList = swappedOutputList.ToArray();
List <ComputedValueDefinition> computeScalareDefinedValues = new List <ComputedValueDefinition>();
foreach (RowBufferEntry rowBufferEntry in node.Left.OutputList)
{
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = rowBufferEntry;
definedValue.Expression = LiteralExpression.FromTypedNull(rowBufferEntry.DataType);
computeScalareDefinedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarNode = new ComputeScalarAlgebraNode();
computeScalarNode.Input = leftAntiSemiJoinNode;
computeScalarNode.DefinedValues = computeScalareDefinedValues.ToArray();
computeScalarNode.OutputList = swappedOutputList.ToArray();
List <UnitedValueDefinition> concatDefinedValues = new List <UnitedValueDefinition>();
for (int i = 0; i < node.OutputList.Length; i++)
{
RowBufferEntry rowBufferEntry = node.OutputList[i];
UnitedValueDefinition concatDefinedValue = new UnitedValueDefinition();
concatDefinedValue.Target = rowBufferEntry;
concatDefinedValue.DependendEntries = new RowBufferEntry[] { node.OutputList[i], node.OutputList[i] };
concatDefinedValues.Add(concatDefinedValue);
}
ConcatAlgebraNode concatenationNode = new ConcatAlgebraNode();
concatenationNode.Inputs = new AlgebraNode[] { leftOuterJoinNode, computeScalarNode };
concatenationNode.DefinedValues = concatDefinedValues.ToArray();
concatenationNode.OutputList = swappedOutputList.ToArray();
return(concatenationNode);
}
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Reorder
//
// A LSJ (B LOJ C) ---> (A LOJ C) LSJ B (LOJ has no join condition and C produces at most one row)
if (node.Op == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin)
{
JoinAlgebraNode rightChildJoin = node.Right as JoinAlgebraNode;
if (rightChildJoin != null &&
rightChildJoin.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
rightChildJoin.Predicate == null &&
AstUtil.WillProduceAtMostOneRow(rightChildJoin.Right))
{
node.Right = rightChildJoin.Left;
rightChildJoin.Left = node.Left;
node.Left = rightChildJoin;
return(VisitAlgebraNode(node));
}
}
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
Visit(node.Left);
Visit(node.Right);
_definedValueEntries.Add(node.ProbeBufferEntry);
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
Visit(node.Left);
Visit(node.Right);
_definedValueEntries.Add(node.ProbeBufferEntry);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
Visit(node.Left);
Visit(node.Right);
node.OuterReferences = AstUtil.GetOuterReferences(node);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
Visit(node.Left);
Visit(node.Right);
node.OuterReferences = AstUtil.GetOuterReferences(node);
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
base.VisitJoinAlgebraNode(node);
if (node.ProbeBufferEntry != null)
NameEntry(node.ProbeBufferEntry, EXPRESSION_NAME_FMT_STR);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
base.VisitJoinAlgebraNode(node);
if (node.ProbeBufferEntry != null)
{
NameEntry(node.ProbeBufferEntry, EXPRESSION_NAME_FMT_STR);
}
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Get declared tables of left and right
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(node.Right);
// Analyze AND-parts of Condition
if (node.Predicate != null)
{
List<ExpressionNode> leftAndParts = new List<ExpressionNode>();
List<ExpressionNode> rightAndParts = new List<ExpressionNode>();
List<ExpressionNode> remainingAndParts = new List<ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
// Check if we can push this AND-part down.
if (AstUtil.AllowsLeftPushDown(node.Op) && AstUtil.ExpressionDoesNotReference(andPart, rightDefinedValues))
{
leftAndParts.Add(andPart);
}
else if (AstUtil.AllowsRightPushDown(node.Op) && AstUtil.ExpressionDoesNotReference(andPart, leftDefinedValues))
{
rightAndParts.Add(andPart);
}
else
{
remainingAndParts.Add(andPart);
}
}
if (leftAndParts.Count > 0)
{
node.Left = GetFilterFromAndParts(leftAndParts, node.Left);
}
if (rightAndParts.Count > 0)
{
node.Right = GetFilterFromAndParts(rightAndParts, node.Right);
}
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
}
// Visit children
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Get declared tables of left and right
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(node.Right);
// Analyze AND-parts of Condition
if (node.Predicate != null)
{
List <ExpressionNode> leftAndParts = new List <ExpressionNode>();
List <ExpressionNode> rightAndParts = new List <ExpressionNode>();
List <ExpressionNode> remainingAndParts = new List <ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
// Check if we can push this AND-part down.
if (AstUtil.AllowsLeftPushDown(node.Op) && AstUtil.ExpressionDoesNotReference(andPart, rightDefinedValues))
{
leftAndParts.Add(andPart);
}
else if (AstUtil.AllowsRightPushDown(node.Op) && AstUtil.ExpressionDoesNotReference(andPart, leftDefinedValues))
{
rightAndParts.Add(andPart);
}
else
{
remainingAndParts.Add(andPart);
}
}
if (leftAndParts.Count > 0)
{
node.Left = GetFilterFromAndParts(leftAndParts, node.Left);
}
if (rightAndParts.Count > 0)
{
node.Right = GetFilterFromAndParts(rightAndParts, node.Right);
}
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
}
// Visit children
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
ShowPlanElement leftElement = ConvertNode(node.Left);
ShowPlanElement rightElement = ConvertNode(node.Right);
PropertyListBuilder propertyListBuilder = new PropertyListBuilder();
AddRowBufferEntries(propertyListBuilder, Resources.ShowPlanGroupOutputList, node.OutputList);
propertyListBuilder.Write(Resources.ShowPlanKeyLogicalOperator, LogicalOperatorToString(node.Op));
AddStatistics(propertyListBuilder, node.StatisticsIterator);
if (node.Predicate != null)
{
propertyListBuilder.Write(Resources.ShowPlanKeyPredicate, node.Predicate.GenerateSource());
}
if (node.OuterReferences != null && node.OuterReferences.Length > 0)
{
AddRowBufferEntries(propertyListBuilder, Resources.ShowPlanGroupOuterReferences, node.OuterReferences);
}
if (node.ProbeBufferEntry != null)
{
WriteRowBufferEntry(propertyListBuilder, Resources.ShowPlanKeyProbeColumn, node.ProbeBufferEntry);
}
if (node.PassthruPredicate != null)
{
propertyListBuilder.Write(Resources.ShowPlanKeyPassthru, node.PassthruPredicate.GenerateSource());
}
// We give a warning if a join has no predicate and no outer reference.
// In this case the join would simply multiply the other side.
// However, we supppress the warning if any side is known at produce at
// most one row.
if (node.Predicate == null &&
(node.OuterReferences == null || node.OuterReferences.Length == 0) &&
!AstUtil.WillProduceAtMostOneRow(node.Left) &&
!AstUtil.WillProduceAtMostOneRow(node.Right))
{
propertyListBuilder.Write(Resources.ShowPlanKeyWarning, Resources.ShowPlanWarningNoJoinPredicate);
}
IList <ShowPlanProperty> properties = propertyListBuilder.ToList();
ShowPlanElement element = new ShowPlanElement(ShowPlanOperator.NestedLoops, properties, leftElement, rightElement);
_currentElement = element;
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
RowBufferEntry[] outerReferences = AstUtil.GetOuterReferences(node);
if (outerReferences != null && outerReferences.Length > 0)
_outerReferences.Push(node.OuterReferences);
node.Right = VisitAlgebraNode(node.Right);
if (outerReferences != null && outerReferences.Length > 0)
_outerReferences.Pop();
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
_xmlWriter.WriteStartElement("joinAlgebraNode");
_xmlWriter.WriteAttributeString("op", node.Op.ToString());
WriteRowBufferEntries("externalColumnDependencies", node.OuterReferences);
WriteAstNode("leftNode", node.Left);
WriteAstNode("rightNode", node.Right);
WriteAstNode("joinCondition", node.Predicate);
_xmlWriter.WriteEndElement();
return(node);
}
private static bool SemiJoinDoesNotDependOn(JoinAlgebraNode.JoinOperator op, ExpressionNode part, RowBufferEntry[] leftDefinedValues, RowBufferEntry[] rightDefinedValues)
{
if (op == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
op == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin)
{
return AstUtil.ExpressionDoesNotReference(part, rightDefinedValues);
}
if (op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin)
{
return AstUtil.ExpressionDoesNotReference(part, leftDefinedValues);
}
return true;
}
public override AstElement Clone(Dictionary <AstElement, AstElement> alreadyClonedElements)
{
JoinAlgebraNode result = new JoinAlgebraNode();
result.StatisticsIterator = StatisticsIterator;
result.OutputList = ArrayHelpers.Clone(OutputList);
result.Left = (AlgebraNode)_left.Clone(alreadyClonedElements);
result.Right = (AlgebraNode)_right.Clone(alreadyClonedElements);
result.Op = _op;
if (_predicate != null)
{
result.Predicate = (ExpressionNode)_predicate.Clone(alreadyClonedElements);
}
result.OuterReferences = ArrayHelpers.Clone(_outerReferences);
return(result);
}
public override ExpressionNode VisitSingleRowSubselect(SingleRowSubselect expression)
{
AlgebraNode inputNode = GetOrCreateInput();
ResultAlgebraNode algebrizedSubquery = Algebrizer.Convert(expression.Query);
ResultAlgebraNode assertedSubquery = CreateAssertedSubquery(algebrizedSubquery);
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.PassthruPredicate = CurrentPassthruPredicate;
joinAlgebraNode.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
joinAlgebraNode.Left = inputNode;
joinAlgebraNode.Right = assertedSubquery;
SetLastAlgebraNode(joinAlgebraNode);
return(new RowBufferEntryExpression(assertedSubquery.OutputList[0]));
}
public static RowBufferEntry[] GetOuterReferences(JoinAlgebraNode node)
{
RowBufferEntry[] leftDefinedValues = GetDefinedValueEntries(node.Left);
RowBufferEntry[] rowBufferEntries = GetRowBufferEntryReferences(node.Right);
List <RowBufferEntry> outerReferenceList = new List <RowBufferEntry>();
foreach (RowBufferEntry rightColumnDependency in rowBufferEntries)
{
if (ArrayHelpers.Contains(leftDefinedValues, rightColumnDependency))
{
outerReferenceList.Add(rightColumnDependency);
}
}
return(outerReferenceList.ToArray());
}
public virtual AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
if (node.Predicate != null)
{
node.Predicate = VisitExpression(node.Predicate);
}
if (node.PassthruPredicate != null)
{
node.PassthruPredicate = VisitExpression(node.PassthruPredicate);
}
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
List <RowBufferEntry> outputList = new List <RowBufferEntry>();
outputList.AddRange(node.Left.OutputList);
outputList.AddRange(node.Right.OutputList);
if (node.ProbeBufferEntry != null)
{
outputList.Add(node.ProbeBufferEntry);
}
node.OutputList = outputList.ToArray();
return(node);
}
public override ExpressionNode VisitExistsSubselect(ExistsSubselect expression)
{
AlgebraNode input = GetAndResetLastNode();
ResultAlgebraNode algebrizedQuery = Algebrizer.Convert(expression.Query);
if (!expression.Negated && AstUtil.WillProduceAtLeastOneRow(algebrizedQuery))
{
if (input == null)
{
SetLastAlgebraNode(CreateConstantScan());
}
else
{
SetLastAlgebraNode(input);
}
return(LiteralExpression.FromBoolean(true));
}
if (!expression.Negated && !ProbingEnabled && input == null)
{
SetLastAlgebraNode(algebrizedQuery);
return(LiteralExpression.FromBoolean(true));
}
else
{
if (input == null)
{
input = CreateConstantScan();
}
RowBufferEntry probeColumn = CreateProbeColumn();
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.PassthruPredicate = CurrentPassthruPredicate;
joinAlgebraNode.ProbeBufferEntry = probeColumn;
joinAlgebraNode.Left = input;
joinAlgebraNode.Right = algebrizedQuery;
joinAlgebraNode.Op = expression.Negated ? JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin : JoinAlgebraNode.JoinOperator.LeftSemiJoin;
SetLastAlgebraNode(joinAlgebraNode);
return(CreateProbeColumnRef(probeColumn));
}
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
if (node.Op != JoinAlgebraNode.JoinOperator.InnerJoin)
{
_consistsOnlyOfInnerJoinsFiltersAndTables = false;
return(node);
}
if (node.Predicate != null)
{
_filters.Add(node.Predicate);
}
Visit(node.Left);
Visit(node.Right);
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// A IJ (B J C) --> (A IJ B) J C
node.Left = VisitAlgebraNode(node.Left);
if (node.Op != JoinAlgebraNode.JoinOperator.InnerJoin)
return node;
JoinAlgebraNode rightSide = node.Right as JoinAlgebraNode;
if (rightSide == null)
return node;
node.Right = rightSide.Left;
rightSide.Left = node;
return VisitAlgebraNode(rightSide);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
RowBufferEntry[] outerReferences = AstUtil.GetOuterReferences(node);
if (outerReferences != null && outerReferences.Length > 0)
{
_outerReferences.Push(node.OuterReferences);
}
node.Right = VisitAlgebraNode(node.Right);
if (outerReferences != null && outerReferences.Length > 0)
{
_outerReferences.Pop();
}
return(node);
}
public static bool JoinDoesNotDependOn(JoinAlgebraNode joinNode, AlgebraNode joinSide)
{
RowBufferEntry[] joinSideDefinedValues = GetDefinedValueEntries(joinSide);
if (joinNode.Predicate != null)
{
RowBufferEntry[] referencedRowBufferEntries = GetRowBufferEntryReferences(joinNode.Predicate);
foreach (RowBufferEntry joinSideDefinedValue in joinSideDefinedValues)
{
if (ArrayHelpers.Contains(referencedRowBufferEntries, joinSideDefinedValue))
{
return(false);
}
}
}
return(true);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// A IJ (B J C) --> (A IJ B) J C
node.Left = VisitAlgebraNode(node.Left);
if (node.Op != JoinAlgebraNode.JoinOperator.InnerJoin)
{
return(node);
}
JoinAlgebraNode rightSide = node.Right as JoinAlgebraNode;
if (rightSide == null)
{
return(node);
}
node.Right = rightSide.Left;
rightSide.Left = node;
return(VisitAlgebraNode(rightSide));
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.OutputList = RemovedUnneededRowBufferColumns(node.OutputList);
if (node.Predicate != null)
{
AddNeededRowBufferEntryReferences(node.Predicate);
}
if (node.PassthruPredicate != null)
{
AddNeededRowBufferEntryReferences(node.PassthruPredicate);
}
if (node.OuterReferences != null)
{
foreach (RowBufferEntry outerReference in node.OuterReferences)
{
AddNeededRowBufferEntry(outerReference);
}
}
return(base.VisitJoinAlgebraNode(node));
}
public override ExpressionNode VisitSingleRowSubselect(SingleRowSubselect expression)
{
AlgebraNode inputNode = GetOrCreateInput();
ResultAlgebraNode algebrizedSubquery = Algebrizer.Convert(expression.Query);
ResultAlgebraNode assertedSubquery = CreateAssertedSubquery(algebrizedSubquery);
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.PassthruPredicate = CurrentPassthruPredicate;
joinAlgebraNode.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
joinAlgebraNode.Left = inputNode;
joinAlgebraNode.Right = assertedSubquery;
SetLastAlgebraNode(joinAlgebraNode);
return new RowBufferEntryExpression(assertedSubquery.OutputList[0]);
}
public override ExpressionNode VisitAllAnySubselect(AllAnySubselect expression)
{
expression.Left = VisitExpression(expression.Left);
ResultAlgebraNode algebrizedQuery = Algebrizer.Convert(expression.Query);
ExpressionNode leftExpression = expression.Left;
RowBufferEntryExpression rightExpression = new RowBufferEntryExpression();
rightExpression.RowBufferEntry = algebrizedQuery.OutputList[0];
ExpressionBuilder expressionBuilder = new ExpressionBuilder();
expressionBuilder.Push(leftExpression);
expressionBuilder.Push(rightExpression);
expressionBuilder.PushBinary(expression.Op);
bool negated = (expression.Type == AllAnySubselect.AllAnyType.All);
if (negated)
{
expressionBuilder.PushUnary(UnaryOperator.LogicalNot);
expressionBuilder.Push(leftExpression);
expressionBuilder.PushIsNull();
expressionBuilder.Push(rightExpression);
expressionBuilder.PushIsNull();
expressionBuilder.PushNAry(LogicalOperator.Or);
}
ExpressionNode filterPredicate = expressionBuilder.Pop();
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = algebrizedQuery;
filterAlgebraNode.Predicate = filterPredicate;
AlgebraNode input = GetAndResetLastNode();
if (!negated && !ProbingEnabled && input == null)
{
SetLastAlgebraNode(filterAlgebraNode);
return LiteralExpression.FromBoolean(true);
}
else
{
if (input == null)
input = CreateConstantScan();
RowBufferEntry probeColumn = CreateProbeColumn();
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.PassthruPredicate = CurrentPassthruPredicate;
joinAlgebraNode.ProbeBufferEntry = probeColumn;
joinAlgebraNode.Left = input;
joinAlgebraNode.Right = filterAlgebraNode;
joinAlgebraNode.Op = negated ? JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin : JoinAlgebraNode.JoinOperator.LeftSemiJoin;
SetLastAlgebraNode(joinAlgebraNode);
return CreateProbeColumnRef(probeColumn);
}
}
public override ExpressionNode VisitExistsSubselect(ExistsSubselect expression)
{
AlgebraNode input = GetAndResetLastNode();
ResultAlgebraNode algebrizedQuery = Algebrizer.Convert(expression.Query);
if (!expression.Negated && AstUtil.WillProduceAtLeastOneRow(algebrizedQuery))
{
if (input == null)
SetLastAlgebraNode(CreateConstantScan());
else
SetLastAlgebraNode(input);
return LiteralExpression.FromBoolean(true);
}
if (!expression.Negated && !ProbingEnabled && input == null)
{
SetLastAlgebraNode(algebrizedQuery);
return LiteralExpression.FromBoolean(true);
}
else
{
if (input == null)
input = CreateConstantScan();
RowBufferEntry probeColumn = CreateProbeColumn();
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.PassthruPredicate = CurrentPassthruPredicate;
joinAlgebraNode.ProbeBufferEntry = probeColumn;
joinAlgebraNode.Left = input;
joinAlgebraNode.Right = algebrizedQuery;
joinAlgebraNode.Op = expression.Negated ? JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin : JoinAlgebraNode.JoinOperator.LeftSemiJoin;
SetLastAlgebraNode(joinAlgebraNode);
return CreateProbeColumnRef(probeColumn);
}
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
if (node.Predicate == null || !AstUtil.ContainsSubselect(node.Predicate))
return base.VisitJoinAlgebraNode(node);
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
switch (node.Op)
{
case JoinAlgebraNode.JoinOperator.InnerJoin:
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Predicate = node.Predicate;
filterAlgebraNode.Input = node;
node.Predicate = null;
SetLastAlgebraNode(node);
_probingEnabledStack.Push(false);
filterAlgebraNode.Predicate = VisitExpression(filterAlgebraNode.Predicate);
_probingEnabledStack.Pop();
filterAlgebraNode.Input = GetAndResetLastNode();
return filterAlgebraNode;
}
case JoinAlgebraNode.JoinOperator.LeftOuterJoin:
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Predicate = node.Predicate;
filterAlgebraNode.Input = node.Right;
node.Right = filterAlgebraNode;
node.Predicate = null;
SetLastAlgebraNode(filterAlgebraNode.Input);
_probingEnabledStack.Push(false);
filterAlgebraNode.Predicate = VisitExpression(filterAlgebraNode.Predicate);
_probingEnabledStack.Pop();
filterAlgebraNode.Input = GetAndResetLastNode();
return node;
}
case JoinAlgebraNode.JoinOperator.RightOuterJoin:
{
node.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
AlgebraNode oldLeft = node.Left;
node.Left = node.Right;
node.Right = oldLeft;
goto case JoinAlgebraNode.JoinOperator.LeftOuterJoin;
}
case JoinAlgebraNode.JoinOperator.FullOuterJoin:
// TODO: Support subqueries in FULL OUTER JOIN.
throw ExceptionBuilder.InternalError("FULL OUTER JOIN containing a subselect predicate in ON clause is not supported.");
default:
throw ExceptionBuilder.UnhandledCaseLabel(node.Op);
}
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Get declared tables of left and right
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(node.Right);
// Replace outer joins by left-/right-/inner joins
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
if (IsAnyNullRejected(leftDefinedValues))
{
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin)
node.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
else
node.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
}
}
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
if (IsAnyNullRejected(rightDefinedValues))
{
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin)
node.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
else
node.Op = JoinAlgebraNode.JoinOperator.RightOuterJoin;
}
}
// After converting an outer join to an inner one we can
// sometimes eliminate the whole join.
if (node.Op == JoinAlgebraNode.JoinOperator.InnerJoin)
{
// TODO: There is a problem. If the constant scan defines values this does not work. Acutally,
// this is currently no problem as the only way to create such a plan is using derived
// tables and in this phase the child will be a ResultNode.
if (node.Left is ConstantScanAlgebraNode)
return VisitAlgebraNode(WrapWithFilter(node.Right, node.Predicate));
if (node.Right is ConstantScanAlgebraNode)
return VisitAlgebraNode(WrapWithFilter(node.Left, node.Predicate));
}
// Analyze AND-parts of Condition
if (node.Predicate == null)
{
// TODO: This does not work as the children are not yet rearranged.
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin)
{
bool hasOuterReferences = AstUtil.GetOuterReferences(node).Length == 0;
if (!hasOuterReferences)
{
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin && AstUtil.WillProduceAtLeastOneRow(node.Right) ||
node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin && AstUtil.WillProduceAtLeastOneRow(node.Left))
{
node.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
return VisitAlgebraNode(node);
}
}
}
}
else
{
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
if (node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
// Check if we can derive from this AND-part that a table it depends on
// is null-rejected.
RowBufferEntry[] rowBufferEntries = AstUtil.GetRowBufferEntryReferences(andPart);
foreach (RowBufferEntry rowBufferEntry in rowBufferEntries)
{
if (AstUtil.ExpressionYieldsNullOrFalseIfRowBufferEntryNull(andPart, rowBufferEntry))
{
if (ArrayHelpers.Contains(leftDefinedValues, rowBufferEntry) &&
node.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin)
{
AddNullRejectedTable(rowBufferEntry);
}
else if (ArrayHelpers.Contains(rightDefinedValues, rowBufferEntry) &&
node.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin)
{
AddNullRejectedTable(rowBufferEntry);
}
}
}
}
}
}
// Visit children
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return node;
}
public override ExpressionNode VisitBinaryExpression(BinaryExpression expression)
{
if (expression.Op != BinaryOperator.LogicalAnd &&
expression.Op != BinaryOperator.LogicalOr)
return base.VisitBinaryExpression(expression);
if (expression.Op == BinaryOperator.LogicalAnd)
{
// AND
expression.Left = VisitExpression(expression.Left);
expression.Right = VisitExpression(expression.Right);
return expression;
}
else
{
// OR
AlgebraNode input = GetAndResetLastNode();
_probingEnabledStack.Push(false);
List<ExpressionNode> scalarOrParts = new List<ExpressionNode>();
List<AlgebraNode> algebrizedOrParts = new List<AlgebraNode>();
foreach (ExpressionNode orPart in AstUtil.SplitCondition(LogicalOperator.Or, expression))
{
if (!AstUtil.ContainsSubselect(orPart))
{
scalarOrParts.Add(orPart);
}
else
{
ExpressionNode replacedOrPart = VisitExpression(orPart);
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = GetAndResetLastNode();
filterAlgebraNode.Predicate = replacedOrPart;
algebrizedOrParts.Add(filterAlgebraNode);
}
}
if (scalarOrParts.Count > 0)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Predicate = AstUtil.CombineConditions(LogicalOperator.Or, scalarOrParts);
filterAlgebraNode.Input = CreateConstantScan();
algebrizedOrParts.Insert(0, filterAlgebraNode);
}
_probingEnabledStack.Pop();
ConcatAlgebraNode concat = new ConcatAlgebraNode();
concat.DefinedValues = new UnitedValueDefinition[0];
concat.Inputs = algebrizedOrParts.ToArray();
RowBufferEntry probeColumn = CreateProbeColumn();
JoinAlgebraNode leftSemiJoinBetweenInputAndConcat = new JoinAlgebraNode();
leftSemiJoinBetweenInputAndConcat.Op = JoinAlgebraNode.JoinOperator.LeftSemiJoin;
leftSemiJoinBetweenInputAndConcat.PassthruPredicate = CurrentPassthruPredicate;
leftSemiJoinBetweenInputAndConcat.ProbeBufferEntry = probeColumn;
leftSemiJoinBetweenInputAndConcat.Left = input;
leftSemiJoinBetweenInputAndConcat.Right = concat;
SetLastAlgebraNode(leftSemiJoinBetweenInputAndConcat);
return CreateProbeColumnRef(probeColumn);
}
}
public static RowBufferEntry[] GetOuterReferences(JoinAlgebraNode node)
{
RowBufferEntry[] leftDefinedValues = GetDefinedValueEntries(node.Left);
RowBufferEntry[] rowBufferEntries = GetRowBufferEntryReferences(node.Right);
List<RowBufferEntry> outerReferenceList = new List<RowBufferEntry>();
foreach (RowBufferEntry rightColumnDependency in rowBufferEntries)
{
if (ArrayHelpers.Contains(leftDefinedValues, rightColumnDependency))
outerReferenceList.Add(rightColumnDependency);
}
return outerReferenceList.ToArray();
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
// Reorder (pull LOJ out of IJ)
//
// (A LOJ B) IJ C ---> (A IJ C) LOJ B (IJ does not depend on B)
// (A ROJ B) IJ C ---> A ROJ (B IJ C) (IJ does not depend on A)
if (node.Op == JoinAlgebraNode.JoinOperator.InnerJoin)
{
JoinAlgebraNode childJoin = node.Left as JoinAlgebraNode;
if (childJoin != null &&
(childJoin.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
childJoin.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin))
{
if (childJoin.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin)
{
if (AstUtil.JoinDoesNotDependOn(node, childJoin.Right))
{
node.Left = childJoin.Left;
childJoin.Left = node;
return(VisitAlgebraNode(childJoin));
}
}
else if (childJoin.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin)
{
if (AstUtil.JoinDoesNotDependOn(node, childJoin.Left))
{
node.Left = childJoin.Right;
childJoin.Right = node;
return(VisitAlgebraNode(childJoin));
}
}
}
}
//// Reorder (push LSJ)
////
//// (A J B) LSJ C ---> (A LSJ C) J B (LSJ does not depend on B)
//// (A J B) LSJ C ---> A J (B LSJ C) (LSJ does not depend on A)
//if (node.Op == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
// node.Op == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin)
//{
// JoinAlgebraNode childJoin = node.Left as JoinAlgebraNode;
// if (childJoin != null)
// {
// if (AstUtil.JoinDoesNotDependOn(node, childJoin.Right))
// {
// node.Left = childJoin.Left;
// childJoin.Left = node;
// return VisitAlgebraNode(childJoin);
// }
// if (AstUtil.JoinDoesNotDependOn(node, childJoin.Left))
// {
// node.Left = childJoin.Right;
// childJoin.Right = node;
// return VisitAlgebraNode(childJoin);
// }
// }
//}
return(node);
}
public static bool JoinDoesNotDependOn(JoinAlgebraNode joinNode, AlgebraNode joinSide)
{
RowBufferEntry[] joinSideDefinedValues = GetDefinedValueEntries(joinSide);
if (joinNode.Predicate != null)
{
RowBufferEntry[] referencedRowBufferEntries = GetRowBufferEntryReferences(joinNode.Predicate);
foreach (RowBufferEntry joinSideDefinedValue in joinSideDefinedValues)
{
if (ArrayHelpers.Contains(referencedRowBufferEntries, joinSideDefinedValue))
return false;
}
}
return true;
}
public static bool AllowsRightPushDown(JoinAlgebraNode.JoinOperator joinOperator)
{
return joinOperator == JoinAlgebraNode.JoinOperator.InnerJoin ||
joinOperator == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
joinOperator == JoinAlgebraNode.JoinOperator.LeftSemiJoin ||
joinOperator == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
joinOperator == JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin ||
joinOperator == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin;
}
public virtual AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
if (node.Predicate != null)
node.Predicate = VisitExpression(node.Predicate);
if (node.PassthruPredicate != null)
node.PassthruPredicate = VisitExpression(node.PassthruPredicate);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
List<RowBufferEntry> outputList = new List<RowBufferEntry>();
outputList.AddRange(node.Left.OutputList);
outputList.AddRange(node.Right.OutputList);
if (node.ProbeBufferEntry != null)
outputList.Add(node.ProbeBufferEntry);
node.OutputList = outputList.ToArray();
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
bool leftIsNull = node.Left is NullScanAlgebraNode;
bool rightIsNull = node.Right is NullScanAlgebraNode;
bool joinConditionAlwaysFalse = false;
if (node.Predicate != null)
{
ExpressionNode predicate = node.Predicate;
ConstantExpression predicateAsConstant = predicate as ConstantExpression;
if (predicateAsConstant != null)
{
if (predicateAsConstant.AsBoolean)
node.Predicate = null;
else
joinConditionAlwaysFalse = true;
}
}
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin)
{
node.SwapSides();
}
switch (node.Op)
{
case JoinAlgebraNode.JoinOperator.InnerJoin:
if (joinConditionAlwaysFalse || leftIsNull || rightIsNull)
return CreateNullScan(node.OutputList);
break;
case JoinAlgebraNode.JoinOperator.FullOuterJoin:
if (leftIsNull && rightIsNull)
return CreateNullScan(node.OutputList);
if (leftIsNull)
return PadRightWithNullsOnLeftSide(node, RowBufferCreationMode.KeepExisting);
if (rightIsNull)
return PadLeftWithNullsOnRightSide(node, RowBufferCreationMode.KeepExisting);
if (joinConditionAlwaysFalse)
{
AlgebraNode left = PadLeftWithNullsOnRightSide(node, RowBufferCreationMode.CreateNew);
AlgebraNode right = PadRightWithNullsOnLeftSide(node, RowBufferCreationMode.CreateNew);
ConcatAlgebraNode concatAlgebraNode = new ConcatAlgebraNode();
concatAlgebraNode.Inputs = new AlgebraNode[] { left, right };
List<RowBufferEntry> outputList = new List<RowBufferEntry>();
List<UnitedValueDefinition> definedValues = new List<UnitedValueDefinition>();
for (int i = 0; i < node.Left.OutputList.Length; i++)
{
int leftIndex = i;
int rightIndex = node.Right.OutputList.Length + i;
UnitedValueDefinition definedValue = new UnitedValueDefinition();
definedValue.Target = node.Left.OutputList[leftIndex];
definedValue.DependendEntries = new RowBufferEntry[] { left.OutputList[leftIndex], right.OutputList[rightIndex] };
definedValues.Add(definedValue);
outputList.Add(definedValue.Target);
}
for (int i = 0; i < node.Right.OutputList.Length; i++)
{
int leftIndex = node.Left.OutputList.Length + i;
int rightIndex = i;
UnitedValueDefinition definedValue = new UnitedValueDefinition();
definedValue.Target = node.Right.OutputList[rightIndex];
definedValue.DependendEntries = new RowBufferEntry[] { left.OutputList[leftIndex], right.OutputList[rightIndex] };
definedValues.Add(definedValue);
outputList.Add(definedValue.Target);
}
concatAlgebraNode.DefinedValues = definedValues.ToArray();
concatAlgebraNode.OutputList = outputList.ToArray();
return concatAlgebraNode;
}
break;
case JoinAlgebraNode.JoinOperator.LeftOuterJoin:
if (leftIsNull)
return CreateNullScan(node.OutputList);
if (rightIsNull || joinConditionAlwaysFalse)
return PadLeftWithNullsOnRightSide(node, RowBufferCreationMode.KeepExisting);
break;
case JoinAlgebraNode.JoinOperator.LeftSemiJoin:
if (leftIsNull || rightIsNull || joinConditionAlwaysFalse)
return CreateNullScan(node.OutputList);
if (node.Predicate == null && AstUtil.WillProduceAtLeastOneRow(node.Right))
return node.Left;
break;
case JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin:
if (leftIsNull)
return CreateNullScan(node.OutputList);
if (rightIsNull || joinConditionAlwaysFalse)
return node.Left;
if (node.Predicate == null && AstUtil.WillProduceAtLeastOneRow(node.Right))
return CreateNullScan(node.OutputList);
break;
}
return node;
}
public override QueryNode VisitBinaryQuery(BinaryQuery query)
{
switch (query.Op)
{
case BinaryQueryOperator.Intersect:
case BinaryQueryOperator.Except:
{
ResultAlgebraNode left = ((ResultAlgebraNode)ConvertAstNode(query.Left));
ResultAlgebraNode right = ((ResultAlgebraNode)ConvertAstNode(query.Right));
// Create distinct sort
SortAlgebraNode sortAlgebraNode = new SortAlgebraNode();
sortAlgebraNode.Distinct = true;
sortAlgebraNode.Input = left;
sortAlgebraNode.SortEntries = left.OutputList;
sortAlgebraNode.SortOrders = CreateAscendingSortOrders(sortAlgebraNode.SortEntries.Length);
// Insert left (anti) semi join to (except) intersect left and right.
ExpressionBuilder expressionBuilder = new ExpressionBuilder();
for (int i = 0; i < left.OutputList.Length; i++)
{
RowBufferEntryExpression leftExpr = new RowBufferEntryExpression();
leftExpr.RowBufferEntry = left.OutputList[i];
RowBufferEntryExpression rightExpr = new RowBufferEntryExpression();
rightExpr.RowBufferEntry = right.OutputList[i];
expressionBuilder.Push(leftExpr);
expressionBuilder.Push(rightExpr);
expressionBuilder.PushBinary(BinaryOperator.Equal);
expressionBuilder.Push(leftExpr);
expressionBuilder.PushIsNull();
expressionBuilder.Push(rightExpr);
expressionBuilder.PushIsNull();
expressionBuilder.PushBinary(BinaryOperator.LogicalAnd);
expressionBuilder.PushBinary(BinaryOperator.LogicalOr);
}
expressionBuilder.PushNAry(LogicalOperator.And);
ExpressionNode joinCondition = expressionBuilder.Pop();
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
if (query.Op == BinaryQueryOperator.Intersect)
{
joinAlgebraNode.Op = JoinAlgebraNode.JoinOperator.LeftSemiJoin;
}
else
{
joinAlgebraNode.Op = JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin;
}
joinAlgebraNode.Left = sortAlgebraNode;
joinAlgebraNode.Right = right;
joinAlgebraNode.Predicate = joinCondition;
SetLastAlgebraNode(joinAlgebraNode);
ResultAlgebraNode resultAlgebraNode = new ResultAlgebraNode();
resultAlgebraNode.Input = GetLastAlgebraNode();
resultAlgebraNode.OutputList = left.OutputList;
resultAlgebraNode.ColumnNames = left.ColumnNames;
SetLastAlgebraNode(resultAlgebraNode);
break;
}
case BinaryQueryOperator.Union:
case BinaryQueryOperator.UnionAll:
{
// Build a flat list with all inputs.
List <QueryNode> inputList = AstUtil.FlattenBinaryQuery(query);
AlgebraNode[] inputs = new AlgebraNode[inputList.Count];
for (int i = 0; i < inputs.Length; i++)
{
inputs[i] = ConvertAstNode(inputList[i]);
}
int outputColumnCount = inputs[0].OutputList.Length;
UnitedValueDefinition[] definedValues = new UnitedValueDefinition[outputColumnCount];
List <RowBufferEntry> definedValueEntries = new List <RowBufferEntry>();
for (int i = 0; i < outputColumnCount; i++)
{
RowBufferEntry rowBufferEntry = new RowBufferEntry(inputs[0].OutputList[i].DataType);
definedValueEntries.Add(rowBufferEntry);
UnitedValueDefinition definedValue = new UnitedValueDefinition();
definedValue.Target = rowBufferEntry;
List <RowBufferEntry> dependencies = new List <RowBufferEntry>();
foreach (ResultAlgebraNode node in inputs)
{
dependencies.Add(node.OutputList[i]);
}
definedValue.DependendEntries = dependencies.ToArray();
definedValues[i] = definedValue;
}
ConcatAlgebraNode concatAlgebraNode = new ConcatAlgebraNode();
concatAlgebraNode.Inputs = inputs;
concatAlgebraNode.DefinedValues = definedValues;
SetLastAlgebraNode(concatAlgebraNode);
if (query.Op == BinaryQueryOperator.Union)
{
SortAlgebraNode sortAlgebraNode = new SortAlgebraNode();
sortAlgebraNode.Distinct = true;
sortAlgebraNode.Input = GetLastAlgebraNode();
sortAlgebraNode.SortEntries = definedValueEntries.ToArray();
sortAlgebraNode.SortOrders = CreateAscendingSortOrders(sortAlgebraNode.SortEntries.Length);
SetLastAlgebraNode(sortAlgebraNode);
}
ResultAlgebraNode unionResultAlgebraNode = new ResultAlgebraNode();
unionResultAlgebraNode.Input = GetLastAlgebraNode();
unionResultAlgebraNode.ColumnNames = ((ResultAlgebraNode)inputs[0]).ColumnNames;
unionResultAlgebraNode.OutputList = definedValueEntries.ToArray();
SetLastAlgebraNode(unionResultAlgebraNode);
break;
}
}
return(query);
}
private void UpdatePredicateRowBufferReferences(NestedLoopsIterator nestedLoopsIterator, JoinAlgebraNode node)
{
BoundRowBufferEntrySet leftBoundRowBufferEntrySet = new BoundRowBufferEntrySet(nestedLoopsIterator.Left.RowBuffer, node.Left.OutputList);
BoundRowBufferEntrySet rightBoundRowBufferEntrySet = new BoundRowBufferEntrySet(nestedLoopsIterator.Right.RowBuffer, node.Right.OutputList);
if (node.Predicate != null)
nestedLoopsIterator.Predicate = CreateRuntimeExpression(node.Predicate, leftBoundRowBufferEntrySet, rightBoundRowBufferEntrySet);
if (node.PassthruPredicate != null)
nestedLoopsIterator.PassthruPredicate = CreateRuntimeExpression(node.PassthruPredicate, leftBoundRowBufferEntrySet, rightBoundRowBufferEntrySet);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
// Get defined values of left and right
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(node.Right);
List<ExpressionNode> andPartsWithinJoin = new List<ExpressionNode>();
// Try to pull up AND-parts that contain outer references from a left sided filter and combine
// them with the join predicate.
//
// NOTE: This is only possible if the join is not a LEFT OUTER or FULL OUTER JOIN since this
// operation would change the join's semantic.
if (node.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
FilterAlgebraNode leftAsFilter = node.Left as FilterAlgebraNode;
if (leftAsFilter != null)
{
List<ExpressionNode> remainingAndParts = new List<ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, leftAsFilter.Predicate))
{
if (AndPartHasOuterReference(andPart, leftDefinedValues))
andPartsWithinJoin.Add(andPart);
else
remainingAndParts.Add(andPart);
}
leftAsFilter.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
if (leftAsFilter.Predicate == null)
node.Left = leftAsFilter.Input;
}
}
// Try to pull up AND-parts that contain outer references from a right sided filter and combine
// them with the join predicate.
//
// NOTE: This is only possible if the join is not a RIGHT OUTER or FULL OUTER JOIN since this
// operation would change the join's semantic.
if (node.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
FilterAlgebraNode rightAsFilter = node.Right as FilterAlgebraNode;
if (rightAsFilter != null)
{
List<ExpressionNode> remainingAndParts = new List<ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, rightAsFilter.Predicate))
{
if (AndPartHasOuterReference(andPart, rightDefinedValues))
andPartsWithinJoin.Add(andPart);
else
remainingAndParts.Add(andPart);
}
rightAsFilter.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
if (rightAsFilter.Predicate == null)
node.Right = rightAsFilter.Input;
}
}
// If we found any AND-parts that could be pulled up, merge them with the join predicate.
if (andPartsWithinJoin.Count > 0)
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, node.Predicate, AstUtil.CombineConditions(LogicalOperator.And, andPartsWithinJoin));
// Now we try to extract AND-parts that contain outer references from the join predicate itself.
//
// NOTE: This is only possible if the node is not an OUTER JOIN. If the node is a SEMI JOIN the
// operation is only legal if the AND-part does not reference any columns from the side that is
// is used as filter criteria (i.e. for LSJ this is the right side, for RSJ this is the left
// side).
if (node.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin &&
node.Predicate != null)
{
List<ExpressionNode> andPartsAboveJoin = new List<ExpressionNode>();
List<ExpressionNode> remainingAndParts = new List<ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
if (AndPartHasOuterReference(andPart, leftDefinedValues, rightDefinedValues) &&
SemiJoinDoesNotDependOn(node.Op, andPart, leftDefinedValues, rightDefinedValues))
andPartsAboveJoin.Add(andPart);
else
remainingAndParts.Add(andPart);
}
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
if (andPartsAboveJoin.Count > 0)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Predicate = AstUtil.CombineConditions(LogicalOperator.And, andPartsAboveJoin);
filterAlgebraNode.Input = node;
return filterAlgebraNode;
}
}
return node;
}
public override AstElement Clone(Dictionary<AstElement, AstElement> alreadyClonedElements)
{
JoinAlgebraNode result = new JoinAlgebraNode();
result.StatisticsIterator = StatisticsIterator;
result.OutputList = ArrayHelpers.Clone(OutputList);
result.Left = (AlgebraNode)_left.Clone(alreadyClonedElements);
result.Right = (AlgebraNode)_right.Clone(alreadyClonedElements);
result.Op = _op;
if (_predicate != null)
result.Predicate = (ExpressionNode)_predicate.Clone(alreadyClonedElements);
result.OuterReferences = ArrayHelpers.Clone(_outerReferences);
return result;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
bool leftIsNull = node.Left is NullScanAlgebraNode;
bool rightIsNull = node.Right is NullScanAlgebraNode;
bool joinConditionAlwaysFalse = false;
if (node.Predicate != null)
{
ExpressionNode predicate = node.Predicate;
ConstantExpression predicateAsConstant = predicate as ConstantExpression;
if (predicateAsConstant != null)
{
if (predicateAsConstant.AsBoolean)
{
node.Predicate = null;
}
else
{
joinConditionAlwaysFalse = true;
}
}
}
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin)
{
node.SwapSides();
}
switch (node.Op)
{
case JoinAlgebraNode.JoinOperator.InnerJoin:
if (joinConditionAlwaysFalse || leftIsNull || rightIsNull)
{
return(CreateNullScan(node.OutputList));
}
break;
case JoinAlgebraNode.JoinOperator.FullOuterJoin:
if (leftIsNull && rightIsNull)
{
return(CreateNullScan(node.OutputList));
}
if (leftIsNull)
{
return(PadRightWithNullsOnLeftSide(node, RowBufferCreationMode.KeepExisting));
}
if (rightIsNull)
{
return(PadLeftWithNullsOnRightSide(node, RowBufferCreationMode.KeepExisting));
}
if (joinConditionAlwaysFalse)
{
AlgebraNode left = PadLeftWithNullsOnRightSide(node, RowBufferCreationMode.CreateNew);
AlgebraNode right = PadRightWithNullsOnLeftSide(node, RowBufferCreationMode.CreateNew);
ConcatAlgebraNode concatAlgebraNode = new ConcatAlgebraNode();
concatAlgebraNode.Inputs = new AlgebraNode[] { left, right };
List <RowBufferEntry> outputList = new List <RowBufferEntry>();
List <UnitedValueDefinition> definedValues = new List <UnitedValueDefinition>();
for (int i = 0; i < node.Left.OutputList.Length; i++)
{
int leftIndex = i;
int rightIndex = node.Right.OutputList.Length + i;
UnitedValueDefinition definedValue = new UnitedValueDefinition();
definedValue.Target = node.Left.OutputList[leftIndex];
definedValue.DependendEntries = new RowBufferEntry[] { left.OutputList[leftIndex], right.OutputList[rightIndex] };
definedValues.Add(definedValue);
outputList.Add(definedValue.Target);
}
for (int i = 0; i < node.Right.OutputList.Length; i++)
{
int leftIndex = node.Left.OutputList.Length + i;
int rightIndex = i;
UnitedValueDefinition definedValue = new UnitedValueDefinition();
definedValue.Target = node.Right.OutputList[rightIndex];
definedValue.DependendEntries = new RowBufferEntry[] { left.OutputList[leftIndex], right.OutputList[rightIndex] };
definedValues.Add(definedValue);
outputList.Add(definedValue.Target);
}
concatAlgebraNode.DefinedValues = definedValues.ToArray();
concatAlgebraNode.OutputList = outputList.ToArray();
return(concatAlgebraNode);
}
break;
case JoinAlgebraNode.JoinOperator.LeftOuterJoin:
if (leftIsNull)
{
return(CreateNullScan(node.OutputList));
}
if (rightIsNull || joinConditionAlwaysFalse)
{
return(PadLeftWithNullsOnRightSide(node, RowBufferCreationMode.KeepExisting));
}
break;
case JoinAlgebraNode.JoinOperator.LeftSemiJoin:
if (leftIsNull || rightIsNull || joinConditionAlwaysFalse)
{
return(CreateNullScan(node.OutputList));
}
if (node.Predicate == null && AstUtil.WillProduceAtLeastOneRow(node.Right))
{
return(node.Left);
}
break;
case JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin:
if (leftIsNull)
{
return(CreateNullScan(node.OutputList));
}
if (rightIsNull || joinConditionAlwaysFalse)
{
return(node.Left);
}
if (node.Predicate == null && AstUtil.WillProduceAtLeastOneRow(node.Right))
{
return(CreateNullScan(node.OutputList));
}
break;
}
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
// Get defined values of left and right
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(node.Right);
List <ExpressionNode> andPartsWithinJoin = new List <ExpressionNode>();
// Try to pull up AND-parts that contain outer references from a left sided filter and combine
// them with the join predicate.
//
// NOTE: This is only possible if the join is not a LEFT OUTER or FULL OUTER JOIN since this
// operation would change the join's semantic.
if (node.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
FilterAlgebraNode leftAsFilter = node.Left as FilterAlgebraNode;
if (leftAsFilter != null)
{
List <ExpressionNode> remainingAndParts = new List <ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, leftAsFilter.Predicate))
{
if (AndPartHasOuterReference(andPart, leftDefinedValues))
{
andPartsWithinJoin.Add(andPart);
}
else
{
remainingAndParts.Add(andPart);
}
}
leftAsFilter.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
if (leftAsFilter.Predicate == null)
{
node.Left = leftAsFilter.Input;
}
}
}
// Try to pull up AND-parts that contain outer references from a right sided filter and combine
// them with the join predicate.
//
// NOTE: This is only possible if the join is not a RIGHT OUTER or FULL OUTER JOIN since this
// operation would change the join's semantic.
if (node.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
FilterAlgebraNode rightAsFilter = node.Right as FilterAlgebraNode;
if (rightAsFilter != null)
{
List <ExpressionNode> remainingAndParts = new List <ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, rightAsFilter.Predicate))
{
if (AndPartHasOuterReference(andPart, rightDefinedValues))
{
andPartsWithinJoin.Add(andPart);
}
else
{
remainingAndParts.Add(andPart);
}
}
rightAsFilter.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
if (rightAsFilter.Predicate == null)
{
node.Right = rightAsFilter.Input;
}
}
}
// If we found any AND-parts that could be pulled up, merge them with the join predicate.
if (andPartsWithinJoin.Count > 0)
{
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, node.Predicate, AstUtil.CombineConditions(LogicalOperator.And, andPartsWithinJoin));
}
// Now we try to extract AND-parts that contain outer references from the join predicate itself.
//
// NOTE: This is only possible if the node is not an OUTER JOIN. If the node is a SEMI JOIN the
// operation is only legal if the AND-part does not reference any columns from the side that is
// is used as filter criteria (i.e. for LSJ this is the right side, for RSJ this is the left
// side).
if (node.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin &&
node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin &&
node.Predicate != null)
{
List <ExpressionNode> andPartsAboveJoin = new List <ExpressionNode>();
List <ExpressionNode> remainingAndParts = new List <ExpressionNode>();
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
if (AndPartHasOuterReference(andPart, leftDefinedValues, rightDefinedValues) &&
SemiJoinDoesNotDependOn(node.Op, andPart, leftDefinedValues, rightDefinedValues))
{
andPartsAboveJoin.Add(andPart);
}
else
{
remainingAndParts.Add(andPart);
}
}
node.Predicate = AstUtil.CombineConditions(LogicalOperator.And, remainingAndParts);
if (andPartsAboveJoin.Count > 0)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Predicate = AstUtil.CombineConditions(LogicalOperator.And, andPartsAboveJoin);
filterAlgebraNode.Input = node;
return(filterAlgebraNode);
}
}
return(node);
}
private void PushOuterReferences(object[] rowBuffer, JoinAlgebraNode node)
{
if (node.OuterReferences != null && node.OuterReferences.Length > 0)
{
// Important: We cannot use node.OuterReferences as argument for BoundRowBufferEntrySet().
// The replacment strategy below will replace occurences to the entries by their index
// within the array. Therefore we need an array with the same layout as the row buffer.
RowBufferEntry[] outerReferences = new RowBufferEntry[node.Left.OutputList.Length];
for (int i = 0; i < outerReferences.Length; i++)
{
if (ArrayHelpers.Contains(node.OuterReferences, node.Left.OutputList[i]))
outerReferences[i] = node.Left.OutputList[i];
}
BoundRowBufferEntrySet bufferEntrySet = new BoundRowBufferEntrySet(rowBuffer, outerReferences);
_outerReferenceStack.Push(bufferEntrySet);
}
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Get declared tables of left and right
RowBufferEntry[] leftDefinedValues = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedValues = AstUtil.GetDefinedValueEntries(node.Right);
// Replace outer joins by left-/right-/inner joins
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
if (IsAnyNullRejected(leftDefinedValues))
{
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin)
{
node.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
}
else
{
node.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
}
}
}
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
if (IsAnyNullRejected(rightDefinedValues))
{
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin)
{
node.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
}
else
{
node.Op = JoinAlgebraNode.JoinOperator.RightOuterJoin;
}
}
}
// After converting an outer join to an inner one we can
// sometimes eliminate the whole join.
if (node.Op == JoinAlgebraNode.JoinOperator.InnerJoin)
{
// TODO: There is a problem. If the constant scan defines values this does not work. Acutally,
// this is currently no problem as the only way to create such a plan is using derived
// tables and in this phase the child will be a ResultNode.
if (node.Left is ConstantScanAlgebraNode)
{
return(VisitAlgebraNode(WrapWithFilter(node.Right, node.Predicate)));
}
if (node.Right is ConstantScanAlgebraNode)
{
return(VisitAlgebraNode(WrapWithFilter(node.Left, node.Predicate)));
}
}
// Analyze AND-parts of Condition
if (node.Predicate == null)
{
// TODO: This does not work as the children are not yet rearranged.
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin)
{
bool hasOuterReferences = AstUtil.GetOuterReferences(node).Length == 0;
if (!hasOuterReferences)
{
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin && AstUtil.WillProduceAtLeastOneRow(node.Right) ||
node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin && AstUtil.WillProduceAtLeastOneRow(node.Left))
{
node.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
return(VisitAlgebraNode(node));
}
}
}
}
else
{
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, node.Predicate))
{
if (node.Op != JoinAlgebraNode.JoinOperator.FullOuterJoin)
{
// Check if we can derive from this AND-part that a table it depends on
// is null-rejected.
RowBufferEntry[] rowBufferEntries = AstUtil.GetRowBufferEntryReferences(andPart);
foreach (RowBufferEntry rowBufferEntry in rowBufferEntries)
{
if (AstUtil.ExpressionYieldsNullOrFalseIfRowBufferEntryNull(andPart, rowBufferEntry))
{
if (ArrayHelpers.Contains(leftDefinedValues, rowBufferEntry) &&
node.Op != JoinAlgebraNode.JoinOperator.LeftOuterJoin)
{
AddNullRejectedTable(rowBufferEntry);
}
else if (ArrayHelpers.Contains(rightDefinedValues, rowBufferEntry) &&
node.Op != JoinAlgebraNode.JoinOperator.RightOuterJoin)
{
AddNullRejectedTable(rowBufferEntry);
}
}
}
}
}
}
// Visit children
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return(node);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
if (node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightAntiSemiJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightSemiJoin)
{
if (node.OuterReferences != null && node.OuterReferences.Length > 0)
throw ExceptionBuilder.InternalError("Outer references should not be possible for {0} and are not supported.", node.Op);
node.SwapSides();
}
NestedLoopsIterator nestedLoopsIterator;
switch (node.Op)
{
case JoinAlgebraNode.JoinOperator.InnerJoin:
nestedLoopsIterator = new InnerNestedLoopsIterator();
break;
case JoinAlgebraNode.JoinOperator.LeftOuterJoin:
nestedLoopsIterator = new LeftOuterNestedLoopsIterator();
break;
case JoinAlgebraNode.JoinOperator.LeftSemiJoin:
if (node.ProbeBufferEntry == null)
nestedLoopsIterator = new LeftSemiNestedLoopsIterator();
else
{
ProbedSemiJoinNestedLoopsIterator probedSemiJoinNestedLoopsIterator = new ProbedSemiJoinNestedLoopsIterator();
probedSemiJoinNestedLoopsIterator.ProbeOutput = GetDefinedValue(node.OutputList, node.ProbeBufferEntry);
nestedLoopsIterator = probedSemiJoinNestedLoopsIterator;
}
break;
case JoinAlgebraNode.JoinOperator.LeftAntiSemiJoin:
if (node.ProbeBufferEntry == null)
nestedLoopsIterator = new LeftAntiSemiNestedLoopsIterator();
else
{
ProbedAntiSemiJoinNestedLoopsIterator probedSemiJoinNestedLoopsIterator = new ProbedAntiSemiJoinNestedLoopsIterator();
probedSemiJoinNestedLoopsIterator.ProbeOutput = GetDefinedValue(node.OutputList, node.ProbeBufferEntry);
nestedLoopsIterator = probedSemiJoinNestedLoopsIterator;
}
break;
default:
throw ExceptionBuilder.UnhandledCaseLabel(node.Op);
}
nestedLoopsIterator.RowBuffer = new object[node.OutputList.Length];
nestedLoopsIterator.Left = ConvertAlgebraNode(node.Left);
nestedLoopsIterator.LeftOutput = GetIteratorOutput(0, node.Left.OutputList, node.OutputList);
PushOuterReferences(nestedLoopsIterator.Left.RowBuffer, node);
nestedLoopsIterator.Right = ConvertAlgebraNode(node.Right);
nestedLoopsIterator.RightOutput = GetIteratorOutput(nestedLoopsIterator.LeftOutput.Length, node.Right.OutputList, node.OutputList);
UpdatePredicateRowBufferReferences(nestedLoopsIterator, node);
if (node.OuterReferences != null && node.OuterReferences.Length > 0)
_outerReferenceStack.Pop();
SetLastIterator(node, nestedLoopsIterator);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Check if node only consists of INNER join nodes and simple table reference nodes.
// This algorithm assumes that the table references have been lineraized so that
//
// - JoinedTableReference appear on the LHS only (the last one must be NamedTableReference ovbiviously)
// - NamedTableReference appear on the RHS only
//
// While scanning the node's children we create a list of all JoinedTableReferences and
// NamedTableReferences.
InnerJoinTableExtractor innerJoinTableExtractor = new InnerJoinTableExtractor();
innerJoinTableExtractor.Visit(node);
if (!innerJoinTableExtractor.ConsistsOnlyOfInnerJoinsFiltersAndTables)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return node;
}
else
{
TableAlgebraNode[] algebraNodes = innerJoinTableExtractor.GetTableNodes();
Dictionary<TableRefBinding,TableAlgebraNode> tableRefToNodeDictionary = new Dictionary<TableRefBinding, TableAlgebraNode>();
List<TableRefBinding> tableList = new List<TableRefBinding>();
foreach (TableAlgebraNode algebraNode in algebraNodes)
{
tableRefToNodeDictionary.Add(algebraNode.TableRefBinding, algebraNode);
tableList.Add(algebraNode.TableRefBinding);
}
// Create a mapping RowBufferEntry -> ColumnRefBinding
Dictionary<RowBufferEntry, ColumnRefBinding> rowBufferColumnDictionary = new Dictionary<RowBufferEntry, ColumnRefBinding>();
foreach (TableRefBinding tableRefBinding in tableList)
{
foreach (ColumnRefBinding columnRefBinding in tableRefBinding.ColumnRefs)
rowBufferColumnDictionary.Add(columnRefBinding.ValueDefinition.Target, columnRefBinding);
}
// Create list of all possible join conditions and remaining AND-parts.
List<JoinCondition> joinConditionList = new List<JoinCondition>();
List<ExpressionNode> andPartList = new List<ExpressionNode>();
ExpressionNode filter = AstUtil.CombineConditions(LogicalOperator.And, innerJoinTableExtractor.GetFilters());
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, filter))
{
JoinCondition joinCondition = ConvertToJoinCondition(rowBufferColumnDictionary, andPart);
if (joinCondition != null)
joinConditionList.Add(joinCondition);
else
andPartList.Add(andPart);
}
// After creating the list of all join conditions and AND-parts we have all we need to create
// an optimimal join order between all tables of this part of the table tree.
JoinOrder bestJoinOrder = GetBestJoinOrder(tableList.ToArray(), joinConditionList.ToArray(), andPartList.ToArray());
// Get all tables that are introduced by this join order
Dictionary<RowBufferEntry, ColumnValueDefinition> introducedColumns = GetIntroducedColumns(bestJoinOrder);
// Combine AND-part list with all unused join conditions.
andPartList.AddRange(bestJoinOrder.UnusedConditions);
// Now we will re-create this part of the tree using the this join order.
AlgebraNode lastAlgebraNode = null;
for (int joinIndex = 0; joinIndex < bestJoinOrder.Joins.Length; joinIndex++)
{
Join join = bestJoinOrder.Joins[joinIndex];
AlgebraNode tableInput;
TableAlgebraNode tableNode = tableRefToNodeDictionary[join.TableRefBinding];
ExpressionNode tableFilter = ExtractConditionsApplicableToTable(introducedColumns, andPartList, join.TableRefBinding);
if (tableFilter == null)
{
tableInput = tableNode;
}
else
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = tableNode;
filterAlgebraNode.Predicate = tableFilter;
tableInput = filterAlgebraNode;
}
if (lastAlgebraNode == null)
{
// This was the first one.
lastAlgebraNode = tableInput;
}
else
{
// Not the first one, we can create a join with the current table reference
// and last table reference.
// Get all AND-parts that can be applied to the tables already joined.
// This expression is merged to one condition.
ExpressionNode[] applicableAndParts = GetAndPartsApplicableToJoin(introducedColumns, bestJoinOrder, joinIndex, andPartList, true);
ExpressionNode condition = AstUtil.CombineConditions(LogicalOperator.And, applicableAndParts);
ExpressionNode joinCondition;
if (join.JoinCondition == null)
joinCondition = null;
else
joinCondition = join.JoinCondition.ToExpression();
ExpressionNode completeCondition = AstUtil.CombineConditions(LogicalOperator.And, condition, joinCondition);
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
joinAlgebraNode.Left = lastAlgebraNode;
joinAlgebraNode.Right = tableInput;
joinAlgebraNode.Predicate = completeCondition;
// Next time this newly created join is the last table reference.
lastAlgebraNode = joinAlgebraNode;
}
}
return lastAlgebraNode;
}
}
private static AlgebraNode AlgebrizeRecursiveCte(CommonTableBinding commonTableBinding)
{
// It is a recursive query.
//
// Create row buffer entry that is used to guard the recursion and the primary table spool
// that spools the results needed by nested recursion calls.
ExpressionBuilder expressionBuilder = new ExpressionBuilder();
StackedTableSpoolAlgebraNode primaryTableSpool = new StackedTableSpoolAlgebraNode();
RowBufferEntry anchorRecursionLevel;
RowBufferEntry[] anchorOutput;
AlgebraNode anchorNode;
#region Anchor member
{
// Emit anchor member.
AlgebraNode algebrizedAnchor = Convert(commonTableBinding.AnchorMember);
// Emit compute scalar that initializes the recursion level to 0.
anchorRecursionLevel = new RowBufferEntry(typeof(int));
ComputedValueDefinition computedValueDefinition1 = new ComputedValueDefinition();
computedValueDefinition1.Target = anchorRecursionLevel;
computedValueDefinition1.Expression = LiteralExpression.FromInt32(0);
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = algebrizedAnchor;
computeScalarAlgebraNode.DefinedValues = new ComputedValueDefinition[] { computedValueDefinition1 };
anchorOutput = algebrizedAnchor.OutputList;
anchorNode = computeScalarAlgebraNode;
}
#endregion
RowBufferEntry incrementedRecursionLevel;
RowBufferEntry[] tableSpoolOutput;
AlgebraNode tableSpoolNode;
#region Table spool
{
// Emit table spool reference.
RowBufferEntry recursionLevelRefEntry = new RowBufferEntry(typeof(int));
tableSpoolOutput = new RowBufferEntry[anchorOutput.Length];
for (int i = 0; i < tableSpoolOutput.Length; i++)
{
tableSpoolOutput[i] = new RowBufferEntry(anchorOutput[i].DataType);
}
StackedTableSpoolRefAlgebraNode tableSpoolReference = new StackedTableSpoolRefAlgebraNode();
tableSpoolReference.PrimarySpool = primaryTableSpool;
tableSpoolReference.DefinedValues = ArrayHelpers.JoinArrays(new RowBufferEntry[] { recursionLevelRefEntry }, tableSpoolOutput);
// Emit compute scalar that increases the recursion level by one and renames
// columns from the spool to the CTE column buffer entries.
expressionBuilder.Push(new RowBufferEntryExpression(recursionLevelRefEntry));
expressionBuilder.Push(LiteralExpression.FromInt32(1));
expressionBuilder.PushBinary(BinaryOperator.Add);
incrementedRecursionLevel = new RowBufferEntry(typeof(int));
ComputedValueDefinition incremenedRecLevelValueDefinition = new ComputedValueDefinition();
incremenedRecLevelValueDefinition.Target = incrementedRecursionLevel;
incremenedRecLevelValueDefinition.Expression = expressionBuilder.Pop();
CteColumnMappingFinder cteColumnMappingFinder = new CteColumnMappingFinder(commonTableBinding, tableSpoolOutput);
foreach (QueryNode recursiveMember in commonTableBinding.RecursiveMembers)
{
cteColumnMappingFinder.Visit(recursiveMember);
}
CteColumnMapping[] cteColumnMappings = cteColumnMappingFinder.GetMappings();
List <ComputedValueDefinition> definedValues = new List <ComputedValueDefinition>();
definedValues.Add(incremenedRecLevelValueDefinition);
foreach (CteColumnMapping cteColumnMapping in cteColumnMappings)
{
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = cteColumnMapping.VirtualBufferEntry;
definedValue.Expression = new RowBufferEntryExpression(cteColumnMapping.SpoolBufferEntry);
definedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = tableSpoolReference;
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
tableSpoolNode = computeScalarAlgebraNode;
}
#endregion
RowBufferEntry[] recursiveOutput;
AlgebraNode recursiveNode;
#region Recursive member(s)
{
// Emit all recursive parts. The join conditions to the recursive part are replaced by simple filters
// in the nested Convert() call.
ConcatAlgebraNode concatAlgebraNode = new ConcatAlgebraNode();
concatAlgebraNode.Inputs = new AlgebraNode[commonTableBinding.RecursiveMembers.Length];
for (int i = 0; i < commonTableBinding.RecursiveMembers.Length; i++)
{
concatAlgebraNode.Inputs[i] = Convert(commonTableBinding, commonTableBinding.RecursiveMembers[i]);
}
concatAlgebraNode.DefinedValues = new UnitedValueDefinition[anchorOutput.Length];
for (int i = 0; i < anchorOutput.Length; i++)
{
List <RowBufferEntry> dependencies = new List <RowBufferEntry>();
foreach (ResultAlgebraNode algebrizedRecursivePart in concatAlgebraNode.Inputs)
{
dependencies.Add(algebrizedRecursivePart.OutputList[i]);
}
concatAlgebraNode.DefinedValues[i] = new UnitedValueDefinition();
concatAlgebraNode.DefinedValues[i].Target = new RowBufferEntry(anchorOutput[i].DataType);
concatAlgebraNode.DefinedValues[i].DependendEntries = dependencies.ToArray();
}
// Calculate the recursive output.
recursiveOutput = new RowBufferEntry[concatAlgebraNode.DefinedValues.Length];
for (int i = 0; i < concatAlgebraNode.DefinedValues.Length; i++)
{
recursiveOutput[i] = concatAlgebraNode.DefinedValues[i].Target;
}
// Emit cross join
JoinAlgebraNode crossJoinNode = new JoinAlgebraNode();
crossJoinNode.Left = tableSpoolNode;
crossJoinNode.Right = concatAlgebraNode;
// Emit assert that ensures that the recursion level is <= 100.
expressionBuilder.Push(new RowBufferEntryExpression(incrementedRecursionLevel));
expressionBuilder.Push(LiteralExpression.FromInt32(100));
expressionBuilder.PushBinary(BinaryOperator.Greater);
CaseExpression caseExpression = new CaseExpression();
caseExpression.WhenExpressions = new ExpressionNode[1];
caseExpression.WhenExpressions[0] = expressionBuilder.Pop();
caseExpression.ThenExpressions = new ExpressionNode[1];
caseExpression.ThenExpressions[0] = LiteralExpression.FromInt32(0);
AssertAlgebraNode assertAlgebraNode = new AssertAlgebraNode();
assertAlgebraNode.Input = crossJoinNode;
assertAlgebraNode.AssertionType = AssertionType.BelowRecursionLimit;
assertAlgebraNode.Predicate = caseExpression;
recursiveNode = assertAlgebraNode;
}
#endregion
RowBufferEntry[] algebrizedOutput;
AlgebraNode algebrizedCte;
#region Combination
{
// Create concat node to combine anchor and recursive part.
ConcatAlgebraNode concatAlgebraNode = new ConcatAlgebraNode();
concatAlgebraNode.Inputs = new AlgebraNode[2];
concatAlgebraNode.Inputs[0] = anchorNode;
concatAlgebraNode.Inputs[1] = recursiveNode;
concatAlgebraNode.DefinedValues = new UnitedValueDefinition[anchorOutput.Length + 1];
concatAlgebraNode.DefinedValues[0] = new UnitedValueDefinition();
concatAlgebraNode.DefinedValues[0].Target = new RowBufferEntry(anchorRecursionLevel.DataType);
concatAlgebraNode.DefinedValues[0].DependendEntries = new RowBufferEntry[] { anchorRecursionLevel, incrementedRecursionLevel };
for (int i = 0; i < anchorOutput.Length; i++)
{
concatAlgebraNode.DefinedValues[i + 1] = new UnitedValueDefinition();
concatAlgebraNode.DefinedValues[i + 1].Target = new RowBufferEntry(anchorOutput[i].DataType);
concatAlgebraNode.DefinedValues[i + 1].DependendEntries = new RowBufferEntry[] { anchorOutput[i], recursiveOutput[i] };
}
algebrizedOutput = new RowBufferEntry[concatAlgebraNode.DefinedValues.Length];
for (int i = 0; i < concatAlgebraNode.DefinedValues.Length; i++)
{
algebrizedOutput[i] = concatAlgebraNode.DefinedValues[i].Target;
}
// Assign the combination as the input to the primray spool
primaryTableSpool.Input = concatAlgebraNode;
// The primary spool represents the result of the "inlined" CTE.
algebrizedCte = primaryTableSpool;
}
#endregion
algebrizedCte.OutputList = algebrizedOutput;
return(algebrizedCte);
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
if (node.Op != JoinAlgebraNode.JoinOperator.InnerJoin)
{
_consistsOnlyOfInnerJoinsFiltersAndTables = false;
return node;
}
if (node.Predicate != null)
_filters.Add(node.Predicate);
Visit(node.Left);
Visit(node.Right);
return node;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
// Check if node only consists of INNER join nodes and simple table reference nodes.
// This algorithm assumes that the table references have been lineraized so that
//
// - JoinedTableReference appear on the LHS only (the last one must be NamedTableReference ovbiviously)
// - NamedTableReference appear on the RHS only
//
// While scanning the node's children we create a list of all JoinedTableReferences and
// NamedTableReferences.
InnerJoinTableExtractor innerJoinTableExtractor = new InnerJoinTableExtractor();
innerJoinTableExtractor.Visit(node);
if (!innerJoinTableExtractor.ConsistsOnlyOfInnerJoinsFiltersAndTables)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
return(node);
}
else
{
TableAlgebraNode[] algebraNodes = innerJoinTableExtractor.GetTableNodes();
Dictionary <TableRefBinding, TableAlgebraNode> tableRefToNodeDictionary = new Dictionary <TableRefBinding, TableAlgebraNode>();
List <TableRefBinding> tableList = new List <TableRefBinding>();
foreach (TableAlgebraNode algebraNode in algebraNodes)
{
tableRefToNodeDictionary.Add(algebraNode.TableRefBinding, algebraNode);
tableList.Add(algebraNode.TableRefBinding);
}
// Create a mapping RowBufferEntry -> ColumnRefBinding
Dictionary <RowBufferEntry, ColumnRefBinding> rowBufferColumnDictionary = new Dictionary <RowBufferEntry, ColumnRefBinding>();
foreach (TableRefBinding tableRefBinding in tableList)
{
foreach (ColumnRefBinding columnRefBinding in tableRefBinding.ColumnRefs)
{
rowBufferColumnDictionary.Add(columnRefBinding.ValueDefinition.Target, columnRefBinding);
}
}
// Create list of all possible join conditions and remaining AND-parts.
List <JoinCondition> joinConditionList = new List <JoinCondition>();
List <ExpressionNode> andPartList = new List <ExpressionNode>();
ExpressionNode filter = AstUtil.CombineConditions(LogicalOperator.And, innerJoinTableExtractor.GetFilters());
foreach (ExpressionNode andPart in AstUtil.SplitCondition(LogicalOperator.And, filter))
{
JoinCondition joinCondition = ConvertToJoinCondition(rowBufferColumnDictionary, andPart);
if (joinCondition != null)
{
joinConditionList.Add(joinCondition);
}
else
{
andPartList.Add(andPart);
}
}
// After creating the list of all join conditions and AND-parts we have all we need to create
// an optimimal join order between all tables of this part of the table tree.
JoinOrder bestJoinOrder = GetBestJoinOrder(tableList.ToArray(), joinConditionList.ToArray(), andPartList.ToArray());
// Get all tables that are introduced by this join order
Dictionary <RowBufferEntry, ColumnValueDefinition> introducedColumns = GetIntroducedColumns(bestJoinOrder);
// Combine AND-part list with all unused join conditions.
andPartList.AddRange(bestJoinOrder.UnusedConditions);
// Now we will re-create this part of the tree using the this join order.
AlgebraNode lastAlgebraNode = null;
for (int joinIndex = 0; joinIndex < bestJoinOrder.Joins.Length; joinIndex++)
{
Join join = bestJoinOrder.Joins[joinIndex];
AlgebraNode tableInput;
TableAlgebraNode tableNode = tableRefToNodeDictionary[join.TableRefBinding];
ExpressionNode tableFilter = ExtractConditionsApplicableToTable(introducedColumns, andPartList, join.TableRefBinding);
if (tableFilter == null)
{
tableInput = tableNode;
}
else
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = tableNode;
filterAlgebraNode.Predicate = tableFilter;
tableInput = filterAlgebraNode;
}
if (lastAlgebraNode == null)
{
// This was the first one.
lastAlgebraNode = tableInput;
}
else
{
// Not the first one, we can create a join with the current table reference
// and last table reference.
// Get all AND-parts that can be applied to the tables already joined.
// This expression is merged to one condition.
ExpressionNode[] applicableAndParts = GetAndPartsApplicableToJoin(introducedColumns, bestJoinOrder, joinIndex, andPartList, true);
ExpressionNode condition = AstUtil.CombineConditions(LogicalOperator.And, applicableAndParts);
ExpressionNode joinCondition;
if (join.JoinCondition == null)
{
joinCondition = null;
}
else
{
joinCondition = join.JoinCondition.ToExpression();
}
ExpressionNode completeCondition = AstUtil.CombineConditions(LogicalOperator.And, condition, joinCondition);
JoinAlgebraNode joinAlgebraNode = new JoinAlgebraNode();
joinAlgebraNode.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
joinAlgebraNode.Left = lastAlgebraNode;
joinAlgebraNode.Right = tableInput;
joinAlgebraNode.Predicate = completeCondition;
// Next time this newly created join is the last table reference.
lastAlgebraNode = joinAlgebraNode;
}
}
return(lastAlgebraNode);
}
}
public override TableReference VisitJoinedTableReference(JoinedTableReference node)
{
TableReference nonCteTableRef;
if (IsTableReferenceToCurrentCommonTableBinding(node.Left))
{
nonCteTableRef = node.Right;
}
else if (IsTableReferenceToCurrentCommonTableBinding(node.Right))
{
nonCteTableRef = node.Left;
}
else
{
nonCteTableRef = null;
}
if (nonCteTableRef != null)
{
Debug.Assert(node.JoinType == JoinType.Inner);
AlgebraNode algebrizedPath = ConvertAstNode(nonCteTableRef);
SetLastAlgebraNode(algebrizedPath);
if (node.Condition != null)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = GetLastAlgebraNode();
filterAlgebraNode.Predicate = node.Condition;
SetLastAlgebraNode(filterAlgebraNode);
}
return(node);
}
JoinAlgebraNode algebraNode = new JoinAlgebraNode();
algebraNode.Left = ConvertAstNode(node.Left);
algebraNode.Right = ConvertAstNode(node.Right);
algebraNode.Predicate = node.Condition;
switch (node.JoinType)
{
case JoinType.Inner:
algebraNode.Op = JoinAlgebraNode.JoinOperator.InnerJoin;
break;
case JoinType.LeftOuter:
algebraNode.Op = JoinAlgebraNode.JoinOperator.LeftOuterJoin;
break;
case JoinType.RightOuter:
algebraNode.Op = JoinAlgebraNode.JoinOperator.RightOuterJoin;
break;
case JoinType.FullOuter:
algebraNode.Op = JoinAlgebraNode.JoinOperator.FullOuterJoin;
break;
}
SetLastAlgebraNode(algebraNode);
return(node);
}