Package org.apache.calcite.rel.rules

Class SubQueryRemoveRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<SubQueryRemoveRule.Config>

org.apache.calcite.rel.rules.SubQueryRemoveRule

All Implemented Interfaces:

TransformationRule

@Enclosing
public class SubQueryRemoveRule
extends RelRule<SubQueryRemoveRule.Config>
implements TransformationRule

Transform that converts IN, EXISTS and scalar sub-queries into joins.

Sub-queries are represented by RexSubQuery expressions.

A sub-query may or may not be correlated. If a sub-query is correlated, the wrapped RelNode will contain a RexCorrelVariable before the rewrite, and the product of the rewrite will be a Correlate. The Correlate can be removed using RelDecorrelator.

See Also:

• CoreRules.FILTER_SUB_QUERY_TO_CORRELATE
• CoreRules.PROJECT_SUB_QUERY_TO_CORRELATE
• CoreRules.JOIN_SUB_QUERY_TO_CORRELATE

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	SubQueryRemoveRule.Config	Rule configuration.

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelRule

RelRule.Done, RelRule.MatchHandler<R extends RelOptRule>, RelRule.OperandBuilder, RelRule.OperandDetailBuilder<R extends RelNode>, RelRule.OperandTransform

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

RelOptRule.ConverterRelOptRuleOperand

Field Summary

Fields inherited from class org.apache.calcite.plan.RelRule

config

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SubQueryRemoveRule(SubQueryRemoveRule.Config config)	Creates a SubQueryRemoveRule.

Method Summary

Modifier and Type	Method	Description
protected RexNode	apply(RexSubQuery e, Set<CorrelationId> variablesSet, RelOptUtil.Logic logic, RelBuilder builder, int inputCount, int offset, int subQueryIndex)
void	onMatch(RelOptRuleCall call)	Receives notification about a rule match.

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

SubQueryRemoveRule

protected SubQueryRemoveRule(SubQueryRemoveRule.Config config)

Creates a SubQueryRemoveRule.

Method Details

onMatch

public void onMatch(RelOptRuleCall call)

Description copied from class: RelOptRule

Receives notification about a rule match. At the time that this method is called, call.rels holds the set of relational expressions which match the operands to the rule; call.rels[0] is the root expression.

Typically a rule would check that the nodes are valid matches, creates a new expression, then calls back RelOptRuleCall.transformTo(org.apache.calcite.rel.RelNode, java.util.Map<org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelNode>, org.apache.calcite.plan.RelHintsPropagator) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

• RelOptRule.matches(RelOptRuleCall)

apply

protected RexNode apply(RexSubQuery e,
 Set<CorrelationId> variablesSet,
 RelOptUtil.Logic logic,
 RelBuilder builder,
 int inputCount,
 int offset,
 int subQueryIndex)