/**
* 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 net.hydromatic.optiq.util.BitSets;
import org.apache.drill.exec.planner.common.DrillProjectRelBase;
import org.apache.drill.exec.planner.logical.DrillAggregateRel;
import org.apache.drill.exec.planner.logical.DrillRel;
import org.apache.drill.exec.planner.logical.DrillSortRel;
import org.apache.drill.exec.planner.logical.RelOptHelper;
import org.apache.drill.exec.planner.physical.DrillDistributionTrait.DistributionField;
import org.eigenbase.rel.RelFieldCollation;
import org.eigenbase.rel.RelNode;
import org.eigenbase.rel.SortRel;
import org.eigenbase.relopt.RelOptRule;
import org.eigenbase.relopt.RelOptRuleCall;
import org.eigenbase.relopt.RelTraitSet;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
/**
*
* Rule that converts a logical {@link DrillSortRel} to a physical sort. Convert from Logical Sort into Physical Sort.
* For Logical Sort, it requires one single data stream as the output.
*
*/
public class SortPrule extends Prule{
public static final RelOptRule INSTANCE = new SortPrule();
private SortPrule() {
super(RelOptHelper.any(DrillSortRel.class, DrillRel.DRILL_LOGICAL), "Prel.SortPrule");
}
@Override
public void onMatch(RelOptRuleCall call) {
final DrillSortRel sort = (DrillSortRel) call.rel(0);
final RelNode input = sort.getChild();
// Keep the collation in logical sort. Convert input into a RelNode with 1) this collation, 2) Physical, 3) hash distributed on
DrillDistributionTrait hashDistribution =
new DrillDistributionTrait(DrillDistributionTrait.DistributionType.HASH_DISTRIBUTED, ImmutableList.copyOf(getDistributionField(sort)));
final RelTraitSet traits = sort.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(hashDistribution);
final RelNode convertedInput = convert(input, traits);
if(isSingleMode(call)){
call.transformTo(convertedInput);
}else{
RelNode exch = new SingleMergeExchangePrel(sort.getCluster(), sort.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON), convertedInput, sort.getCollation());
call.transformTo(exch); // transform logical "sort" into "SingleMergeExchange".
}
}
private List<DistributionField> getDistributionField(DrillSortRel rel) {
List<DistributionField> distFields = Lists.newArrayList();
for (RelFieldCollation relField : rel.getCollation().getFieldCollations()) {
DistributionField field = new DistributionField(relField.getFieldIndex());
distFields.add(field);
}
return distFields;
}
}