org.apache.calcite.plan.hep

Class HepRuleCall

java.lang.Object

org.apache.calcite.plan.RelOptRuleCall

org.apache.calcite.plan.hep.HepRuleCall

public class HepRuleCall
extends RelOptRuleCall

HepRuleCall implements RelOptRuleCall for a HepPlanner. It remembers transformation results so that the planner can choose which one (if any) should replace the original expression.

Field Summary

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

id, LOGGER, nodeInputs, operand0, rels, rule

Method Summary

Modifier and Type	Method and Description
void	transformTo(RelNode rel, Map<RelNode,RelNode> equiv, RelHintsPropagator handler) Registers that a rule has produced an equivalent relational expression.

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

builder, getChildRels, getMetadataQuery, getOperand0, getParents, getPlanner, getRelList, getRels, getRule, isRuleExcluded, rel, setChildRels, transformTo, transformTo, transformTo

Methods inherited from class java.lang.Object

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

Method Detail

transformTo

public void transformTo(RelNode rel,
                        Map<RelNode,RelNode> equiv,
                        RelHintsPropagator handler)

Description copied from class: RelOptRuleCall

Registers that a rule has produced an equivalent relational expression.

Called by the rule whenever it finds a match. The implementation of this method guarantees that the original relational expression (that is, this.rels[0]) has its traits propagated to the new relational expression (rel) and its unregistered children. Any trait not specifically set in the RelTraitSet returned by rel.getTraits() will be copied from this.rels[0].getTraitSet().

The hints of the root relational expression of the rule call(this.rels[0]) are copied to the new relational expression(rel) with specified handler handler.

Specified by:

transformTo in class RelOptRuleCall

Parameters:

rel - Relational expression equivalent to the root relational expression of the rule call, call.rels(0)

equiv - Map of other equivalences

handler - Handler to customize the relational expression that registers into the planner, the first parameter is the root relational expression and the second parameter is the new relational expression