| /* |
| * 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.store; |
| |
| import org.apache.calcite.plan.volcano.RelSubset; |
| import org.apache.calcite.rel.RelNode; |
| import org.apache.calcite.rel.RelShuttle; |
| import org.apache.calcite.rel.RelShuttleImpl; |
| |
| /** |
| * Removes {@link RelSubset} nodes from the plan. |
| * It may be useful when we want to do some operations on the plan |
| * which aren't supported by {@link RelSubset} during the planning phase. |
| */ |
| public class SubsetRemover extends RelShuttleImpl { |
| public static RelShuttle INSTANCE = new SubsetRemover(); |
| |
| @Override |
| public RelNode visit(RelNode other) { |
| if (other instanceof RelSubset) { |
| return ((RelSubset) other).getBest().accept(this); |
| } else { |
| return super.visit(other); |
| } |
| } |
| } |