/**
* 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.apache.drill.exec.planner.physical;
import java.util.List;
import java.util.logging.Logger;
import org.apache.drill.exec.planner.logical.DrillJoinRel;
import org.apache.drill.exec.planner.logical.RelOptHelper;
import org.eigenbase.rel.InvalidRelException;
import org.eigenbase.rel.RelCollation;
import org.eigenbase.rel.RelCollationImpl;
import org.eigenbase.rel.RelFieldCollation;
import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.RelOptRule;
import org.eigenbase.relopt.RelOptRuleCall;
import org.eigenbase.trace.EigenbaseTrace;
import com.google.common.collect.Lists;
public class MergeJoinPrule extends JoinPruleBase {
public static final RelOptRule INSTANCE = new MergeJoinPrule();
protected static final Logger tracer = EigenbaseTrace.getPlannerTracer();
private MergeJoinPrule() {
super(
RelOptHelper.any(DrillJoinRel.class),
"Prel.MergeJoinPrule");
}
@Override
public boolean matches(RelOptRuleCall call) {
return PrelUtil.getPlannerSettings(call.getPlanner()).isMergeJoinEnabled();
}
@Override
public void onMatch(RelOptRuleCall call) {
final DrillJoinRel join = (DrillJoinRel) call.rel(0);
final RelNode left = join.getLeft();
final RelNode right = join.getRight();
if (!checkPreconditions(join, left, right)) {
return;
}
boolean hashSingleKey = PrelUtil.getPlannerSettings(call.getPlanner()).isHashSingleKey();
try {
RelCollation collationLeft = getCollation(join.getLeftKeys());
RelCollation collationRight = getCollation(join.getRightKeys());
createDistBothPlan(call, join, PhysicalJoinType.MERGE_JOIN, left, right, collationLeft, collationRight, hashSingleKey);
if (checkBroadcastConditions(call.getPlanner(), join, left, right)) {
createBroadcastPlan(call, join, PhysicalJoinType.MERGE_JOIN, left, right, collationLeft, collationRight);
}
} catch (InvalidRelException e) {
tracer.warning(e.toString());
}
}
private RelCollation getCollation(List<Integer> keys){
List<RelFieldCollation> fields = Lists.newArrayList();
for (int key : keys) {
fields.add(new RelFieldCollation(key));
}
return RelCollationImpl.of(fields);
}
}