org.apache.druid.sql.calcite.rule.DruidUnionRule Maven / Gradle / Ivy
/*
* 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.druid.sql.calcite.rule;
import org.apache.calcite.plan.RelOptRule;
import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.core.Union;
import org.apache.druid.sql.calcite.rel.DruidRel;
import org.apache.druid.sql.calcite.rel.DruidUnionRel;
import java.util.List;
public class DruidUnionRule extends RelOptRule
{
private static final DruidUnionRule INSTANCE = new DruidUnionRule();
private DruidUnionRule()
{
super(operand(Union.class, unordered(operand(DruidRel.class, any()))));
}
public static DruidUnionRule instance()
{
return INSTANCE;
}
@Override
public void onMatch(final RelOptRuleCall call)
{
final Union unionRel = call.rel(0);
final DruidRel someDruidRel = call.rel(1);
final List inputs = unionRel.getInputs();
if (unionRel.all) {
// Can only do UNION ALL.
call.transformTo(DruidUnionRel.create(
someDruidRel.getQueryMaker(),
unionRel.getRowType(),
inputs,
-1
));
}
}
}