| /* |
| * 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; |
| |
| /** |
| * Rule that creates a {@link DruidUnionRel} from some {@link DruidRel} inputs. |
| */ |
| public class DruidUnionRule extends RelOptRule |
| { |
| private static final DruidUnionRule INSTANCE = new DruidUnionRule(); |
| |
| private DruidUnionRule() |
| { |
| super( |
| operand( |
| Union.class, |
| operand(DruidRel.class, none()), |
| operand(DruidRel.class, none()) |
| ) |
| ); |
| } |
| |
| public static DruidUnionRule instance() |
| { |
| return INSTANCE; |
| } |
| |
| @Override |
| public boolean matches(RelOptRuleCall call) |
| { |
| // Make DruidUnionRule and DruidUnionDataSourceRule mutually exclusive. |
| return !DruidUnionDataSourceRule.instance().matches(call); |
| } |
| |
| @Override |
| public void onMatch(final RelOptRuleCall call) |
| { |
| final Union unionRel = call.rel(0); |
| final DruidRel<?> someDruidRel = call.rel(1); |
| final List<RelNode> inputs = unionRel.getInputs(); |
| |
| // Can only do UNION ALL. |
| if (unionRel.all) { |
| call.transformTo( |
| DruidUnionRel.create( |
| someDruidRel.getQueryMaker(), |
| unionRel.getRowType(), |
| inputs, |
| -1 |
| ) |
| ); |
| } |
| } |
| } |