/**
* 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 com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import net.hydromatic.linq4j.Ord;
import org.eigenbase.rel.UnionRelBase;
import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.*;
import java.util.ArrayList;
import java.util.List;
/**
* Union implemented in Drill.
*/
public class DrillUnionRel extends UnionRelBase implements DrillRel {
/** Creates a DrillUnionRel. */
public DrillUnionRel(RelOptCluster cluster, RelTraitSet traits,
List<RelNode> inputs, boolean all) {
super(cluster, traits, inputs, all);
}
@Override
public DrillUnionRel copy(RelTraitSet traitSet, List<RelNode> inputs,
boolean all) {
return new DrillUnionRel(getCluster(), traitSet, inputs, all);
}
@Override
public RelOptCost computeSelfCost(RelOptPlanner planner) {
// divide cost by two to ensure cheaper than EnumerableDrillRel
return super.computeSelfCost(planner).multiplyBy(.5);
}
@Override
public int implement(DrillImplementor implementor) {
List<Integer> inputIds = new ArrayList<>();
for (Ord<RelNode> input : Ord.zip(inputs)) {
inputIds.add(implementor.visitChild(this, input.i, input.e));
}
/*
E.g. {
op: "union",
distinct: true,
inputs: [2, 4]
}
*/
final ObjectNode union = implementor.mapper.createObjectNode();
union.put("op", "union");
union.put("distinct", !all);
final ArrayNode inputs = implementor.mapper.createArrayNode();
union.put("inputs", inputs);
for (Integer inputId : inputIds) {
inputs.add(inputId);
}
return implementor.add(union);
}
}