/**
* 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 org.apache.drill.exec.planner.common.DrillScreenRelBase;
import org.apache.drill.exec.planner.logical.DrillLimitRel;
import org.apache.drill.exec.planner.logical.DrillRel;
import org.apache.drill.exec.planner.logical.DrillScreenRel;
import org.apache.drill.exec.planner.logical.RelOptHelper;
import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.RelOptRule;
import org.eigenbase.relopt.RelOptRuleCall;
import org.eigenbase.relopt.RelTraitSet;
public class LimitPrule extends Prule{
public static final RelOptRule INSTANCE = new LimitPrule();
public LimitPrule() {
super(RelOptHelper.any(DrillLimitRel.class, DrillRel.DRILL_LOGICAL), "Prel.LimitPrule");
}
@Override
public void onMatch(RelOptRuleCall call) {
final DrillLimitRel limit = (DrillLimitRel) call.rel(0);
final RelNode input = limit.getChild();
final RelTraitSet traits = input.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON);
final RelNode convertedInput = convert(input, traits);
LimitPrel newLimit = new LimitPrel(limit.getCluster(), limit.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON), convertedInput, limit.getOffset(), limit.getFetch());
call.transformTo(newLimit);
}
}