xiedeyantu commented on code in PR #4397: URL: https://github.com/apache/calcite/pull/4397#discussion_r2117276190
########## core/src/main/java/org/apache/calcite/rel/rules/BottomUpDecorrelateRule.java: ########## @@ -0,0 +1,105 @@ +/* + * 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.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Correlate; +import org.apache.calcite.sql2rel.RelDecorrelator; + +import org.immutables.value.Value; + +import java.util.ArrayList; +import java.util.List; + +/** + * This rule invokes the standard decorrelator {@link RelDecorrelator} on subplans of a query + * plan that are rooted at a {@link Correlate} node. By invoking this rule repeatedly + * one essentially obtains a bottom-up application of the decorrelator, where + * {@link Correlate} nodes closer to leaves are processed first. This strategy may + * enable decorrelating plans where applying the decorrelator at the root may fail. + * (The standard decorrelator is all-or-nothing, if it fails, it returns the original plan + * unchanged. This strategy may still simplify some plans by decorrelating parts of them). + */ [email protected] +public class BottomUpDecorrelateRule + extends RelRule<BottomUpDecorrelateRule.Config> + implements TransformationRule { + + protected BottomUpDecorrelateRule(Config config) { + super(config); + } + + //~ Methods ---------------------------------------------------------------- + + @Override public void onMatch(RelOptRuleCall call) { + Correlate cor = call.rel(0); + for (RelNode input : cor.stripped().getInputs()) { + if (containsCorrelate(input)) { Review Comment: The `cor` is `Correlate` type, we may not need to call `stripped()`. This `input` may be `RelSubset` or `HepRelVertex`, and it need to call `stripped()` I think. In `testNestedCorrelate`, the two `LogicalCorrelate ` are not consecutive, so it can execute correctly? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
