org.apache.calcite.rel.rules

Class JoinExtractFilterRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.rel.rules.JoinExtractFilterRule

public final class JoinExtractFilterRule
extends RelOptRule

Rule to convert an inner join to a filter on top of a cartesian inner join.

One benefit of this transformation is that after it, the join condition can be combined with conditions and expressions above the join. It also makes the FennelCartesianJoinRule applicable.

The constructor is parameterized to allow any sub-class of Join, not just LogicalJoin.

Field Summary

Fields

Modifier and Type	Field and Description
static JoinExtractFilterRule	INSTANCE The singleton.

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

description, operands

Constructor Summary

Constructors

Constructor and Description
JoinExtractFilterRule(Class<? extends Join> clazz) Creates an JoinExtractFilterRule.

Method Summary

Methods

Modifier and Type	Method and Description
void	onMatch(RelOptRuleCall call) Receives notification about a rule match.

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

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

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final JoinExtractFilterRule INSTANCE

The singleton.

Constructor Detail

JoinExtractFilterRule

public JoinExtractFilterRule(Class<? extends Join> clazz)

Creates an JoinExtractFilterRule.

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)