org.apache.calcite.sql2rel

Class RelDecorrelator

java.lang.Object

org.apache.calcite.sql2rel.RelDecorrelator

All Implemented Interfaces:

ReflectiveVisitor

public class RelDecorrelator
extends Object
implements ReflectiveVisitor

RelDecorrelator replaces all correlated expressions (corExp) in a relational expression (RelNode) tree with non-correlated expressions that are produced from joining the RelNode that produces the corExp with the RelNode that references it.

TODO:

• replace CorelMap constructor parameter with a RelNode
• make currentRel immutable (would require a fresh RelDecorrelator for each node being decorrelated)
• make fields of CorelMap immutable
• make sub-class rules static, and have them create their own de-correlator

Note: make all the members protected scope so that they can be accessed by the sub-class.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RelDecorrelator.AdjustProjectForCountAggregateRule Planner rule that adjusts projects when counts are added.
static interface	RelDecorrelator.Config Base configuration for rules that are non-static in a RelDecorrelator.
protected static class	RelDecorrelator.CorelMap A map of the locations of Correlate in a tree of RelNodes.
static class	RelDecorrelator.CorelMapBuilder Builds a RelDecorrelator.CorelMap.
static class	RelDecorrelator.RemoveCorrelationForScalarAggregateRule Planner rule that removes correlations for scalar aggregates.
static class	RelDecorrelator.RemoveCorrelationForScalarProjectRule Planner rule that removes correlations for scalar projects.
static class	RelDecorrelator.RemoveSingleAggregateRule Rule to remove an Aggregate with SINGLE_VALUE.

Field Summary

Fields

Modifier and Type	Field and Description
protected RelDecorrelator.CorelMap	cm
protected Context	context
protected @Nullable RelNode	currentRel
protected ReflectUtil.MethodDispatcher<org.apache.calcite.sql2rel.RelDecorrelator.Frame>	dispatcher
protected HashSet<Correlate>	generatedCorRels
protected Map<RelNode,org.apache.calcite.sql2rel.RelDecorrelator.Frame>	map Built during decorrelation, of rel to all the newly created correlated variables in its output, and to map old input positions to new input positions.
protected RelBuilder	relBuilder

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RelDecorrelator(RelDecorrelator.CorelMap cm, Context context, RelBuilder relBuilder)

Method Summary

Modifier and Type	Method and Description
protected RelNode	decorrelate(RelNode root)
protected RexNode	decorrelateExpr(RelNode currentRel, Map<RelNode,org.apache.calcite.sql2rel.RelDecorrelator.Frame> map, RelDecorrelator.CorelMap cm, RexNode exp)
static RelNode	decorrelateQuery(RelNode rootRel) Deprecated.
static RelNode	decorrelateQuery(RelNode rootRel, RelBuilder relBuilder) Decorrelates a query.
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Aggregate rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Correlate rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Filter rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Join rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalAggregate rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalCorrelate rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalFilter rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalJoin rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalProject rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalSnapshot rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(LogicalTableFunctionScan rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Project rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(RelNode rel, boolean isCorVarDefined) Fallback if none of the other decorrelateRel methods match.
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Sort rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	decorrelateRel(Values rel, boolean isCorVarDefined)
@Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame	getInvoke(RelNode r, boolean isCorVarDefined, @Nullable RelNode parent)
protected Collection<RelOptRule>	getPostDecorrelateRules() Returns the rules applied on the rel after decorrelation, never null.
protected RelDecorrelator	getVisitor() Returns the visitor on which the MethodDispatcher dispatches each decorrelateRel method, the default implementation returns this instance, if you got a sub-class, override this method to replace the visitor as the sub-class instance.
protected RelBuilderFactory	relBuilderFactory()
protected RexNode	removeCorrelationExpr(RexNode exp, boolean projectPulledAboveLeftCorrelator)
protected RexNode	removeCorrelationExpr(RexNode exp, boolean projectPulledAboveLeftCorrelator, RexInputRef nullIndicator)
protected RexNode	removeCorrelationExpr(RexNode exp, boolean projectPulledAboveLeftCorrelator, Set<Integer> isCount)
RelNode	removeCorrelationViaRule(RelNode root)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

relBuilder

protected final RelBuilder relBuilder

cm

protected RelDecorrelator.CorelMap cm

dispatcher

protected final ReflectUtil.MethodDispatcher<org.apache.calcite.sql2rel.RelDecorrelator.Frame> dispatcher

currentRel

protected @Nullable RelNode currentRel

context

protected final Context context

map

protected final Map<RelNode,org.apache.calcite.sql2rel.RelDecorrelator.Frame> map

Built during decorrelation, of rel to all the newly created correlated variables in its output, and to map old input positions to new input positions. This is from the view point of the parent rel of a new rel.

generatedCorRels

protected final HashSet<Correlate> generatedCorRels

Constructor Detail

RelDecorrelator

protected RelDecorrelator(RelDecorrelator.CorelMap cm,
                          Context context,
                          RelBuilder relBuilder)

Method Detail

decorrelateQuery

@Deprecated
public static RelNode decorrelateQuery(RelNode rootRel)

Deprecated.

decorrelateQuery

public static RelNode decorrelateQuery(RelNode rootRel,
                                       RelBuilder relBuilder)

Decorrelates a query.

This is the main entry point to RelDecorrelator.

Parameters:

rootRel - Root node of the query

relBuilder - Builder for relational expressions

Returns:

Equivalent query with all Correlate instances removed

relBuilderFactory

protected RelBuilderFactory relBuilderFactory()

decorrelate

protected RelNode decorrelate(RelNode root)

removeCorrelationViaRule

public RelNode removeCorrelationViaRule(RelNode root)

decorrelateExpr

protected RexNode decorrelateExpr(RelNode currentRel,
                                  Map<RelNode,org.apache.calcite.sql2rel.RelDecorrelator.Frame> map,
                                  RelDecorrelator.CorelMap cm,
                                  RexNode exp)

removeCorrelationExpr

protected RexNode removeCorrelationExpr(RexNode exp,
                                        boolean projectPulledAboveLeftCorrelator)

removeCorrelationExpr

protected RexNode removeCorrelationExpr(RexNode exp,
                                        boolean projectPulledAboveLeftCorrelator,
                                        RexInputRef nullIndicator)

removeCorrelationExpr

protected RexNode removeCorrelationExpr(RexNode exp,
                                        boolean projectPulledAboveLeftCorrelator,
                                        Set<Integer> isCount)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(RelNode rel,
                                                                                 boolean isCorVarDefined)

Fallback if none of the other decorrelateRel methods match.

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Sort rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Values rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalAggregate rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Aggregate rel,
                                                                                 boolean isCorVarDefined)

getInvoke

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame getInvoke(RelNode r,
                                                                            boolean isCorVarDefined,
                                                                            @Nullable RelNode parent)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalProject rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Project rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalSnapshot rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalTableFunctionScan rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalFilter rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Filter rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalCorrelate rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Correlate rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(LogicalJoin rel,
                                                                                 boolean isCorVarDefined)

decorrelateRel

public @Nullable org.apache.calcite.sql2rel.RelDecorrelator.Frame decorrelateRel(Join rel,
                                                                                 boolean isCorVarDefined)

getVisitor

protected RelDecorrelator getVisitor()

Returns the visitor on which the MethodDispatcher dispatches each decorrelateRel method, the default implementation returns this instance, if you got a sub-class, override this method to replace the visitor as the sub-class instance.

getPostDecorrelateRules

protected Collection<RelOptRule> getPostDecorrelateRules()

Returns the rules applied on the rel after decorrelation, never null.