Package org.apache.calcite.rel.rules

Class SemiJoinProjectTransposeRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.rel.rules.SemiJoinProjectTransposeRule

public class SemiJoinProjectTransposeRule
extends RelOptRule

Planner rule that pushes a SemiJoin down in a tree past a Project.

The intention is to trigger other rules that will convert SemiJoins.

SemiJoin(LogicalProject(X), Y) → LogicalProject(SemiJoin(X, Y))

See Also:

SemiJoinFilterTransposeRule

Field Summary

Fields

Modifier and Type	Field	Description
static SemiJoinProjectTransposeRule	INSTANCE

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

description, operands, relBuilderFactory

Constructor Summary

Constructors

Modifier	Constructor	Description
private	SemiJoinProjectTransposeRule(RelBuilderFactory relBuilderFactory)	Creates a SemiJoinProjectTransposeRule.

Method Summary

Modifier and Type	Method	Description
private RexNode	adjustCondition(LogicalProject project, SemiJoin semiJoin)	Pulls the project above the semijoin and returns the resulting semijoin condition.
void	onMatch(RelOptRuleCall call)	Receives notification about a rule match.

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

any, 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

Field Detail

INSTANCE

public static final SemiJoinProjectTransposeRule INSTANCE

Constructor Detail

SemiJoinProjectTransposeRule

private SemiJoinProjectTransposeRule(RelBuilderFactory relBuilderFactory)

Creates a SemiJoinProjectTransposeRule.

Method Detail

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>) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

RelOptRule.matches(RelOptRuleCall)

adjustCondition

private RexNode adjustCondition(LogicalProject project,
                                SemiJoin semiJoin)

Pulls the project above the semijoin and returns the resulting semijoin condition. As a result, the semijoin condition should be modified such that references to the LHS of a semijoin should now reference the children of the project that's on the LHS.

Parameters:

project - LogicalProject on the LHS of the semijoin

semiJoin - the semijoin

Returns:

the modified semijoin condition