zabetak commented on a change in pull request #884: [CALCITE-2621] New rule: SemiJoinToCorrelateRule (SemiJoin => LogicalCorrelate) (Ruben Quesada Lopez) URL: https://github.com/apache/calcite/pull/884#discussion_r261568901
########## File path: core/src/main/java/org/apache/calcite/rel/rules/SemiJoinToCorrelateRule.java ########## @@ -0,0 +1,44 @@ +/* + * 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.calcite.rel.rules; + +import org.apache.calcite.rel.core.RelFactories; +import org.apache.calcite.rel.core.SemiJoin; +import org.apache.calcite.tools.RelBuilderFactory; + +/** + * Rule that converts a {@link org.apache.calcite.rel.core.SemiJoin} + * into a {@link org.apache.calcite.rel.logical.LogicalCorrelate}, which can + * then be implemented using nested loops. + */ +public class SemiJoinToCorrelateRule extends JoinToCorrelateRule { Review comment: The way is the code right now there is no reason to add a new subclass. You could put the singleton instance directly in the superclass. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
