/**
* 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.optiq;
import org.eigenbase.rel.UnionRel;
import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.*;
import java.util.ArrayList;
import java.util.List;
/**
* Rule that converts a {@link UnionRel} to a {@link DrillUnionRel}, implemented by a "union" operation.
*/
public class DrillUnionRule extends RelOptRule {
public static final RelOptRule INSTANCE = new DrillUnionRule();
private DrillUnionRule() {
super(RelOptRule.any(UnionRel.class, Convention.NONE), "DrillUnionRule");
}
@Override
public void onMatch(RelOptRuleCall call) {
final UnionRel union = (UnionRel) call.rel(0);
final RelTraitSet traits = union.getTraitSet().plus(DrillRel.CONVENTION);
final List<RelNode> convertedInputs = new ArrayList<>();
for (RelNode input : union.getInputs()) {
final RelNode convertedInput = convert(input, traits);
convertedInputs.add(convertedInput);
}
call.transformTo(new DrillUnionRel(union.getCluster(), traits, convertedInputs, union.all));
}
}