silundong commented on code in PR #4392: URL: https://github.com/apache/calcite/pull/4392#discussion_r2113654418
########## core/src/main/java/org/apache/calcite/rel/rules/ConflictDetectionHelper.java: ########## @@ -0,0 +1,216 @@ +/* + * 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.JoinRelType; + +import com.google.common.collect.ImmutableMap; + +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** + * Conflict detection algorithm based on CD-C. More details are in paper: + * <a href="https://15721.courses.cs.cmu.edu/spring2019/papers/23-optimizer2/p493-moerkotte.pdf";> + * On the correct and complete enumeration of the core search space</a>. + */ +public class ConflictDetectionHelper { + + private ConflictDetectionHelper() { + } + + private static final ImmutableMap<JoinRelType, Integer> INDEX_OF_TABLE = + ImmutableMap.<JoinRelType, Integer>builder() + .put(JoinRelType.INNER, 0).put(JoinRelType.SEMI, 1).put(JoinRelType.ANTI, 2) + .put(JoinRelType.LEFT, 3).put(JoinRelType.FULL, 4).build(); + + // TODO: when special attribute is null rejecting, left/full join is + // associative/left_asscom/right_asscom. See table2/3 in paper + private static final boolean[][] ASSOCIATIVE_TABLE = { + // inner-B semi-B anti-B left-B full-B + /* inner-A */ {true, true, true, true, false}, + /* semi-A */ {false, false, false, false, false}, + /* anti-A */ {false, false, false, false, false}, + /* left-A */ {false, false, false, false, false}, + /* full-A */ {false, false, false, false, false}}; + + private static final boolean[][] LEFT_ASSCOM_TABLE = { + // inner-B semi-B anti-B left-B full-B + /* inner-A */ {true, true, true, true, false}, + /* semi-A */ {true, true, true, true, false}, + /* anti-A */ {true, true, true, true, false}, + /* left-A */ {true, true, true, true, false}, + /* full-A */ {false, false, false, false, false}}; + + private static final boolean[][] RIGHT_ASSCOM_TABLE = { + // inner-B semi-B anti-B left-B full-B + /* inner-A */ {true, false, false, false, false}, + /* semi-A */ {false, false, false, false, false}, + /* anti-A */ {false, false, false, false, false}, + /* left-A */ {false, false, false, false, false}, + /* full-A */ {false, false, false, false, false}}; + + /** + * Make conflict rules for join operator based on CD-C. + * + * @param leftSubEdges left sub operators + * @param rightSubEdges right sub operators + * @param joinType current join operator + * @return a map from table set1 to table set2 that if set1 and the tables in the current join + * operator have an intersection, then set2 must be included in the current join operator + */ + public static Map<Long, Long> makeConflictRules( Review Comment: Got it. But before calling this method, `JoinToHyperGraphRule` has already checked the type of the left and right children of the Join node. If it is a `HyperGraph`, it extracts the hyperedges to leftSubEdges and rightSubEdges, and shifts the bitmap for rightSubEdges. If this method only takes Join node, then the above operations need to be repeated, so it takes three necessary arguments here. -- 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]
