public static bool WillProduceAtMostOneRow(AlgebraNode algebraNode)
{
AtMostOneRowChecker atMostOneRowChecker = new AtMostOneRowChecker();
atMostOneRowChecker.Visit(algebraNode);
return(atMostOneRowChecker.WillProduceAtMostOneRow);
}
private AlgebraNode GetLastAlgebraNode()
{
AlgebraNode result = _lastAlgebraNode;
_lastAlgebraNode = null;
return(result);
}
public static RowBufferEntry[] GetDefinedValueEntries(AlgebraNode node)
{
DefinedValuesFinder definedValuesFinder = new DefinedValuesFinder();
definedValuesFinder.Visit(node);
return(definedValuesFinder.GetDefinedValueEntries());
}
public override TableReference VisitDerivedTableReference(DerivedTableReference node)
{
AlgebraNode algebrizedQuery = Convert(node.Query);
List <ComputedValueDefinition> definedValues = new List <ComputedValueDefinition>();
for (int i = 0; i < node.DerivedTableBinding.ColumnRefs.Length; i++)
{
RowBufferEntry targetRowBufferEntry = node.DerivedTableBinding.ColumnRefs[i].ValueDefinition.Target;
RowBufferEntry sourceRowBufferEntry = algebrizedQuery.OutputList[i];
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = targetRowBufferEntry;
definedValue.Expression = new RowBufferEntryExpression(sourceRowBufferEntry);
definedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = algebrizedQuery;
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
SetLastAlgebraNode(computeScalarAlgebraNode);
return(node);
}
private ShowPlanElement ConvertNode(AlgebraNode node)
{
Visit(node);
ShowPlanElement result = _currentElement;
_currentElement = null;
return(result);
}
public static ShowPlanElement Convert(AlgebraNode algebraNode)
{
if (algebraNode == null)
return new ShowPlanElement(ShowPlanOperator.Select, new ShowPlanProperty[0]);
ShowPlanBuilder showPlanBuilder = new ShowPlanBuilder();
return showPlanBuilder.ConvertNode(algebraNode);
}
private static ResultAlgebraNode Convert(CommonTableBinding currentCommonTableBinding, QueryNode queryNode)
{
Algebrizer algebrizer = new Algebrizer(currentCommonTableBinding);
AlgebraNode result = algebrizer.ConvertAstNode(queryNode);
result = new SubqueryExpander().VisitAlgebraNode(result);
return((ResultAlgebraNode)result);
}
private static AlgebraNode WrapWithFilter(AlgebraNode input, ExpressionNode predicate)
{
if (predicate == null)
return input;
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = input;
filterAlgebraNode.Predicate = predicate;
return filterAlgebraNode;
}
private AlgebraNode GetOrCreateInput()
{
AlgebraNode lastNode = GetAndResetLastNode();
if (lastNode != null)
{
return(lastNode);
}
return(CreateConstantScan());
}
public static ShowPlanElement Convert(AlgebraNode algebraNode)
{
if (algebraNode == null)
{
return(new ShowPlanElement(ShowPlanOperator.Select, new ShowPlanProperty[0]));
}
ShowPlanBuilder showPlanBuilder = new ShowPlanBuilder();
return(showPlanBuilder.ConvertNode(algebraNode));
}
private void SetLastIterator(AlgebraNode owner, Iterator iterator)
{
if (_includeStatistics && owner.StatisticsIterator == null)
{
owner.StatisticsIterator = new StatisticsIterator();
owner.StatisticsIterator.RowBuffer = iterator.RowBuffer;
owner.StatisticsIterator.Input = iterator;
iterator = owner.StatisticsIterator;
}
_lastIterator = iterator;
}
private static AlgebraNode WrapWithFilter(AlgebraNode input, ExpressionNode predicate)
{
if (predicate == null)
{
return(input);
}
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = input;
filterAlgebraNode.Predicate = predicate;
return(filterAlgebraNode);
}
private bool CheckIfNodeHasDependenciesToOuterReferences(AlgebraNode node)
{
foreach (RowBufferEntry rowBufferEntryReference in AstUtil.GetRowBufferEntryReferences(node))
{
foreach (RowBufferEntry[] outerReferences in _outerReferences)
{
if (ArrayHelpers.Contains(outerReferences, rowBufferEntryReference))
{
return(true);
}
}
}
return(false);
}
public override TableReference VisitNamedTableReference(NamedTableReference node)
{
CommonTableBinding tableBindingAsCommonTable = node.TableRefBinding.TableBinding as CommonTableBinding;
if (tableBindingAsCommonTable == null)
{
// It is a regular table reference. Emit just a table node.
List <ColumnValueDefinition> definedValues = new List <ColumnValueDefinition>();
foreach (ColumnRefBinding columnRefBinding in node.TableRefBinding.ColumnRefs)
{
definedValues.Add(columnRefBinding.ValueDefinition);
}
TableAlgebraNode algebraNode = new TableAlgebraNode();
algebraNode.TableRefBinding = node.TableRefBinding;
algebraNode.DefinedValues = definedValues.ToArray();
SetLastAlgebraNode(algebraNode);
}
else
{
// It is a reference to a CTE. Instead of emitting a table node we have to replace the
// reference to the CTE by the algebrized representation of the CTE. One could speak
// of "inlining" the CTE.
if (tableBindingAsCommonTable == _currentCommonTableBinding)
{
// This should never happen. The JoinAlgebraNode should ignore these table references.
Debug.Fail("The current common table binding should never be reached as a table reference.");
}
AlgebraNode algebrizedCte;
if (tableBindingAsCommonTable.IsRecursive)
{
algebrizedCte = AlgebrizeRecursiveCte(tableBindingAsCommonTable);
}
else
{
algebrizedCte = Convert(tableBindingAsCommonTable.AnchorMember);
}
// In order to use the CTE we have to instantiate it. See commonets in InstantiateCte() for
// details.
AlgebraNode computeScalarAlgebraNode = InstantiateCte(algebrizedCte, tableBindingAsCommonTable, node.TableRefBinding);
SetLastAlgebraNode(computeScalarAlgebraNode);
}
return(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 AstNode Visit(AstNode node)
{
node = base.Visit(node);
AlgebraNode algebraNode = node as AlgebraNode;
if (algebraNode != null && algebraNode.OutputList != null)
{
for (int i = 0; i < algebraNode.OutputList.Length; i++)
{
algebraNode.OutputList[i] = ReplaceRowBuffer(algebraNode.OutputList[i]);
}
}
return(node);
}
private static AlgebraNode InstantiateCte(AlgebraNode algebrizedCte, CommonTableBinding commonTableBinding, TableRefBinding commonTableRefBinding)
{
// Replace row buffers to base tables by new ones. This must be done because a CTE could be referenced multiple times.
// Since same row buffer entries means that the underlying data will be stored in the same physical data slot this
// will lead to problems if, for example, two instances of the same CTE are joined together. Any join condition that
// operates on the same column will always compare data coming from the same join side (and therefor will always
// evaluate to true).
//
// Some notes on the implementation:
//
// 1. Note that just replacing references to row buffers of base tables in RowBufferExpression is not enough;
// instead they must also be replaced in output lists, defined value references (esp. ConcatAlgebraNode) etc.
// 2. Also note that although the QueryNodes are re-algebrized every time a CTE is references the expressions
// are still copied from the QueryNodes (instead of cloned). Therefore two algrebrized CTEs will share the same
// expression AST instances. That means that replacing the row buffers leads to failure.
// HACK: This is a workaround for issue 2. However,
// I am not quite sure how one should implement row buffer entry replacement without cloning the algebrized query.
algebrizedCte = (AlgebraNode)algebrizedCte.Clone();
CteTableDefinedValuesReinitializer cteTableDefinedValuesReinitializer = new CteTableDefinedValuesReinitializer();
cteTableDefinedValuesReinitializer.Visit(algebrizedCte);
RowBufferEntry[] outputList = algebrizedCte.OutputList;
int skipRecursionLevel = commonTableBinding.IsRecursive ? 1 : 0;
// Rename the query columns to the CTE columns
List <ComputedValueDefinition> definedValues = new List <ComputedValueDefinition>();
for (int i = 0; i < commonTableRefBinding.ColumnRefs.Length; i++)
{
RowBufferEntry targetRowBufferEntry = commonTableRefBinding.ColumnRefs[i].ValueDefinition.Target;
RowBufferEntry sourceRowBufferEntry = outputList[i + skipRecursionLevel];
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = targetRowBufferEntry;
definedValue.Expression = new RowBufferEntryExpression(sourceRowBufferEntry);
definedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = algebrizedCte;
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
return(computeScalarAlgebraNode);
}
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 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 void SwapSides()
{
AlgebraNode oldLeft = _left;
_left = _right;
_right = oldLeft;
switch (_op)
{
case JoinOperator.LeftOuterJoin:
_op = JoinOperator.RightOuterJoin;
break;
case JoinOperator.LeftSemiJoin:
_op = JoinOperator.RightSemiJoin;
break;
case JoinOperator.LeftAntiSemiJoin:
_op = JoinOperator.RightAntiSemiJoin;
break;
case JoinOperator.RightOuterJoin:
_op = JoinOperator.LeftOuterJoin;
break;
case JoinOperator.RightSemiJoin:
_op = JoinOperator.LeftSemiJoin;
break;
case JoinOperator.RightAntiSemiJoin:
_op = JoinOperator.LeftAntiSemiJoin;
break;
case JoinOperator.InnerJoin:
case JoinOperator.FullOuterJoin:
// Nothing to do.
break;
default:
throw ExceptionBuilder.UnhandledCaseLabel(_op);
}
}
public void SwapSides()
{
AlgebraNode oldLeft = _left;
_left = _right;
_right = oldLeft;
switch (_op)
{
case JoinOperator.LeftOuterJoin:
_op = JoinOperator.RightOuterJoin;
break;
case JoinOperator.LeftSemiJoin:
_op = JoinOperator.RightSemiJoin;
break;
case JoinOperator.LeftAntiSemiJoin:
_op = JoinOperator.RightAntiSemiJoin;
break;
case JoinOperator.RightOuterJoin:
_op = JoinOperator.LeftOuterJoin;
break;
case JoinOperator.RightSemiJoin:
_op = JoinOperator.LeftSemiJoin;
break;
case JoinOperator.RightAntiSemiJoin:
_op = JoinOperator.LeftAntiSemiJoin;
break;
case JoinOperator.InnerJoin:
case JoinOperator.FullOuterJoin:
// Nothing to do.
break;
default:
throw ExceptionBuilder.UnhandledCaseLabel(_op);
}
}
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 static AlgebraNode InstantiateCte(AlgebraNode algebrizedCte, CommonTableBinding commonTableBinding, TableRefBinding commonTableRefBinding)
{
// Replace row buffers to base tables by new ones. This must be done because a CTE could be referenced multiple times.
// Since same row buffer entries means that the underlying data will be stored in the same physical data slot this
// will lead to problems if, for example, two instances of the same CTE are joined together. Any join condition that
// operates on the same column will always compare data coming from the same join side (and therefor will always
// evaluate to true).
//
// Some notes on the implementation:
//
// 1. Note that just replacing references to row buffers of base tables in RowBufferExpression is not enough;
// instead they must also be replaced in output lists, defined value references (esp. ConcatAlgebraNode) etc.
// 2. Also note that although the QueryNodes are re-algebrized every time a CTE is references the expressions
// are still copied from the QueryNodes (instead of cloned). Therefore two algrebrized CTEs will share the same
// expression AST instances. That means that replacing the row buffers leads to failure.
// HACK: This is a workaround for issue 2. However,
// I am not quite sure how one should implement row buffer entry replacement without cloning the algebrized query.
algebrizedCte = (AlgebraNode) algebrizedCte.Clone();
CteTableDefinedValuesReinitializer cteTableDefinedValuesReinitializer = new CteTableDefinedValuesReinitializer();
cteTableDefinedValuesReinitializer.Visit(algebrizedCte);
RowBufferEntry[] outputList = algebrizedCte.OutputList;
int skipRecursionLevel = commonTableBinding.IsRecursive ? 1 : 0;
// Rename the query columns to the CTE columns
List<ComputedValueDefinition> definedValues = new List<ComputedValueDefinition>();
for (int i = 0; i < commonTableRefBinding.ColumnRefs.Length; i++)
{
RowBufferEntry targetRowBufferEntry = commonTableRefBinding.ColumnRefs[i].ValueDefinition.Target;
RowBufferEntry sourceRowBufferEntry = outputList[i + skipRecursionLevel];
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = targetRowBufferEntry;
definedValue.Expression = new RowBufferEntryExpression(sourceRowBufferEntry);
definedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = algebrizedCte;
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
return computeScalarAlgebraNode;
}
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);
}
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 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;
}
public virtual AlgebraNode VisitAlgebraNode(AlgebraNode node)
{
return((AlgebraNode)Visit(node));
}
internal static ShowPlan Build(AlgebraNode root)
{
ShowPlanElement rootElement = ShowPlanBuilder.Convert(root);
return new ShowPlan(rootElement);
}
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 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);
}
private void SetLastAlgebraNode(AlgebraNode algebraNode)
{
_lastAlgebraNode = algebraNode;
}
private static FilterAlgebraNode GetFilterFromAndParts(IList<ExpressionNode> andParts, AlgebraNode input)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = input;
filterAlgebraNode.Predicate = AstUtil.CombineConditions(LogicalOperator.And, andParts);
return filterAlgebraNode;
}
public override AlgebraNode VisitJoinAlgebraNode(JoinAlgebraNode node)
{
node.Left = VisitAlgebraNode(node.Left);
node.Right = VisitAlgebraNode(node.Right);
if (node.Predicate != null &&
(node.OuterReferences == null || node.OuterReferences.Length == 0) &&
(
node.Op == JoinAlgebraNode.JoinOperator.InnerJoin ||
node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.RightOuterJoin ||
node.Op == JoinAlgebraNode.JoinOperator.FullOuterJoin)
)
{
RowBufferEntry[] leftDefinedEntries = AstUtil.GetDefinedValueEntries(node.Left);
RowBufferEntry[] rightDefinedEntries = AstUtil.GetDefinedValueEntries(node.Right);
EqualPredicatesExtractor equalPredicatesExtractor = new EqualPredicatesExtractor(leftDefinedEntries, rightDefinedEntries);
ExpressionNode probeResidual = equalPredicatesExtractor.VisitExpression(node.Predicate);
BinaryExpression[] equalPredicates = equalPredicatesExtractor.GetEqualPredicates();
if (equalPredicates.Length > 0)
{
BinaryExpression equalPredicate = equalPredicates[0];
ExpressionBuilder expressionBuilder = new ExpressionBuilder();
expressionBuilder.Push(probeResidual);
if (equalPredicates.Length > 1)
{
for (int i = 1; i < equalPredicates.Length; i++)
{
expressionBuilder.Push(equalPredicates[i]);
}
expressionBuilder.PushNAry(LogicalOperator.And);
}
probeResidual = expressionBuilder.Pop();
if (probeResidual is ConstantExpression)
{
probeResidual = null;
}
AlgebraNode leftInput = node.Left;
AlgebraNode rightInput = node.Right;
if (node.Op == JoinAlgebraNode.JoinOperator.LeftOuterJoin)
{
node.Op = JoinAlgebraNode.JoinOperator.RightOuterJoin;
leftInput = node.Right;
rightInput = node.Left;
ExpressionNode oldLeft = equalPredicate.Left;
equalPredicate.Left = equalPredicate.Right;
equalPredicate.Right = oldLeft;
}
RowBufferEntry leftEntry;
RowBufferEntryExpression leftAsRowBufferEntryExpression = equalPredicate.Left as RowBufferEntryExpression;
if (leftAsRowBufferEntryExpression != null)
{
leftEntry = leftAsRowBufferEntryExpression.RowBufferEntry;
}
else
{
leftEntry = new RowBufferEntry(equalPredicate.Left.ExpressionType);
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = leftEntry;
definedValue.Expression = equalPredicate.Left;
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = leftInput;
computeScalarAlgebraNode.DefinedValues = new ComputedValueDefinition[] { definedValue };
leftInput = computeScalarAlgebraNode;
}
RowBufferEntry rightEntry;
RowBufferEntryExpression rightAsRowBufferEntryExpression = equalPredicate.Right as RowBufferEntryExpression;
if (rightAsRowBufferEntryExpression != null)
{
rightEntry = rightAsRowBufferEntryExpression.RowBufferEntry;
}
else
{
rightEntry = new RowBufferEntry(equalPredicate.Right.ExpressionType);
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = rightEntry;
definedValue.Expression = equalPredicate.Right;
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = rightInput;
computeScalarAlgebraNode.DefinedValues = new ComputedValueDefinition[] { definedValue };
rightInput = computeScalarAlgebraNode;
}
HashMatchAlgebraNode hashMatchAlgebraNode = new HashMatchAlgebraNode();
hashMatchAlgebraNode.Op = node.Op;
hashMatchAlgebraNode.Left = leftInput;
hashMatchAlgebraNode.Right = rightInput;
hashMatchAlgebraNode.BuildKeyEntry = leftEntry;
hashMatchAlgebraNode.ProbeEntry = rightEntry;
hashMatchAlgebraNode.ProbeResidual = probeResidual;
return(hashMatchAlgebraNode);
}
}
return(node);
}
private void SetLastAlgebraNode(AlgebraNode algebraNode)
{
_lastAlgebraNode = algebraNode;
}
private bool CheckIfNodeHasDependenciesToOuterReferences(AlgebraNode node)
{
foreach (RowBufferEntry rowBufferEntryReference in AstUtil.GetRowBufferEntryReferences(node))
{
foreach (RowBufferEntry[] outerReferences in _outerReferences)
{
if (ArrayHelpers.Contains(outerReferences, rowBufferEntryReference))
return true;
}
}
return false;
}
public virtual AlgebraNode VisitAlgebraNode(AlgebraNode node)
{
return (AlgebraNode)Visit(node);
}
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 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));
}
}
private AlgebraNode GetAndResetLastNode()
{
AlgebraNode result = _lastAlgebraNode;
_lastAlgebraNode = null;
return result;
}
private ShowPlanElement ConvertNode(AlgebraNode node)
{
Visit(node);
ShowPlanElement result = _currentElement;
_currentElement = null;
return result;
}
public static bool WillProduceAtMostOneRow(AlgebraNode algebraNode)
{
AtMostOneRowChecker atMostOneRowChecker = new AtMostOneRowChecker();
atMostOneRowChecker.Visit(algebraNode);
return atMostOneRowChecker.WillProduceAtMostOneRow;
}
private static FilterAlgebraNode GetFilterFromAndParts(IList <ExpressionNode> andParts, AlgebraNode input)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = input;
filterAlgebraNode.Predicate = AstUtil.CombineConditions(LogicalOperator.And, andParts);
return(filterAlgebraNode);
}
private Iterator ConvertAlgebraNode(AlgebraNode algebraNode)
{
Visit(algebraNode);
Iterator iterator = GetLastIterator();
return iterator;
}
public static RowBufferEntry[] GetDefinedValueEntries(AlgebraNode node)
{
DefinedValuesFinder definedValuesFinder = new DefinedValuesFinder();
definedValuesFinder.Visit(node);
return definedValuesFinder.GetDefinedValueEntries();
}
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 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;
}
