- All Implemented Interfaces:
semi-joinfrom a join tree.
It is invoked after attempts have been made to convert a SemiJoin to an indexed scan on a join factor have failed. Namely, if the join factor does not reduce to a single table that can be scanned using an index.
It should only be enabled if all SemiJoins in the plan are advisory; that is, they can be safely dropped without affecting the semantics of the query.
- See Also:
Nested Class SummaryModifier and TypeClassDescription
static interfaceRule 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
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
(SemiJoinRemoveRule.Config config)Creates a SemiJoinRemoveRule.
onMatchpublic void onMatch
(RelOptRuleCall call)Description copied from class:
RelOptRuleReceives notification about a rule match. At the time that this method is called,
call.relsholds the set of relational expressions which match the operands to the rule;
call.relsis 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.