/*
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to you under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/
package org.eigenbase.rel.rules;
import org.eigenbase.rel.JoinRelBase;
import org.eigenbase.rel.RelFactories;
import org.eigenbase.rel.RelNode;
import org.eigenbase.rel.metadata.RelMetadataQuery;
import org.eigenbase.relopt.RelOptPredicateList;
import org.eigenbase.relopt.RelOptRule;
import org.eigenbase.relopt.RelOptRuleCall;
import org.eigenbase.rex.RexBuilder;
import org.eigenbase.rex.RexUtil;
/**
* A Rule to apply inferred predicates from
* {@link org.eigenbase.rel.metadata.RelMdPredicates}.
*
* <p>Predicates returned in {@link org.eigenbase.relopt.RelOptPredicateList}
* are applied appropriately.
*/
public class TransitivePredicatesOnJoinRule extends RelOptRule {
private final RelFactories.FilterFactory filterFactory;
/** The singleton. */
public static final TransitivePredicatesOnJoinRule INSTANCE =
new TransitivePredicatesOnJoinRule(JoinRelBase.class,
RelFactories.DEFAULT_FILTER_FACTORY);
public TransitivePredicatesOnJoinRule(Class<? extends JoinRelBase> clazz,
RelFactories.FilterFactory filterFactory) {
super(operand(clazz, any()));
this.filterFactory = filterFactory;
}
@Override
public void onMatch(RelOptRuleCall call) {
JoinRelBase join = call.rel(0);
RelOptPredicateList preds = RelMetadataQuery.getPulledUpPredicates(join);
if (preds.leftInferredPredicates.isEmpty()
&& preds.rightInferredPredicates.isEmpty()) {
return;
}
RexBuilder rB = join.getCluster().getRexBuilder();
RelNode lChild = join.getLeft();
RelNode rChild = join.getRight();
if (preds.leftInferredPredicates.size() > 0) {
RelNode curr = lChild;
lChild = filterFactory.createFilter(lChild,
RexUtil.composeConjunction(rB, preds.leftInferredPredicates, false));
call.getPlanner().onCopy(curr, lChild);
}
if (preds.rightInferredPredicates.size() > 0) {
RelNode curr = rChild;
rChild = filterFactory.createFilter(rChild,
RexUtil.composeConjunction(rB, preds.rightInferredPredicates, false));
call.getPlanner().onCopy(curr, rChild);
}
RelNode newRel = join.copy(join.getTraitSet(), join.getCondition(),
lChild, rChild, join.getJoinType(), join.isSemiJoinDone());
call.getPlanner().onCopy(join, newRel);
call.transformTo(newRel);
}
}
// End TransitivePredicatesOnJoinRule.java