mihaibudiu commented on code in PR #4280: URL: https://github.com/apache/calcite/pull/4280#discussion_r2023871952
########## core/src/main/java/org/apache/calcite/rel/rules/JoinConditionOrExpansionRule.java: ########## @@ -0,0 +1,115 @@ +/* + * 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.RelOptUtil; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.core.Join; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.tools.RelBuilder; + +import org.immutables.value.Value; + +import java.util.ArrayList; +import java.util.List; + +/** + * Planner rule that matches a + * {@link org.apache.calcite.rel.core.Join} + * and expands OR clauses in join conditions. + * + * <p>For example, for the following SQL query: + * <pre> + * SELECT * + * FROM t1 + * JOIN t2 + * ON (t1.id = t2.id OR t1.name = t2.name) + * </pre> + * + * <p>To + * + * <pre> + * SELECT * + * FROM t1 + * JOIN t2 + * ON t1.id = t2.id + * UNION ALL + * SELECT * + * FROM t1 + * JOIN t2 + * ON t1.name = t2.name + * </pre> + * + * <p>this rule would expand the OR condition into + * two separate join conditions, allowing the optimizer + * to handle these conditions more effectively. + */ [email protected] +public class JoinConditionOrExpansionRule + extends RelRule<JoinConditionOrExpansionRule.Config> + implements TransformationRule { + + /** Creates an JoinConditionExpansionOrRule. */ + protected JoinConditionOrExpansionRule(Config config) { + super(config); + } + + //~ Methods ---------------------------------------------------------------- + + @Override public void onMatch(RelOptRuleCall call) { + Join join = call.rel(0); + RelBuilder relBuilder = call.builder(); + List<RexNode> orConds = RelOptUtil.disjunctions(join.getCondition()); + + if (orConds.size() <= 1) { + return; + } + + List<RexNode> extraConds = new ArrayList<>(); + for (int i = 0; i < orConds.size(); i++) { + RexNode orCond = orConds.get(i); + for (int j = 0; j < i; j++) { + orCond = relBuilder.and(orCond, relBuilder.not(extraConds.get(j))); + } + extraConds.add(orCond); + relBuilder.push(join.getLeft()) + .push(join.getRight()) + .join(join.getJoinType(), orCond); + } + + relBuilder.union(true, orConds.size()); + call.transformTo(relBuilder.build()); + } + + /** Rule configuration. */ + @Value.Immutable + public interface Config extends RelRule.Config { + Config DEFAULT = ImmutableJoinConditionOrExpansionRule.Config.of() + .withOperandFor(Join.class); + + @Override default JoinConditionOrExpansionRule toRule() { + return new JoinConditionOrExpansionRule(this); + } + + /** Defines an operand tree for the given classes. */ + default Config withOperandFor(Class<? extends Join> joinClass) { + return withOperandSupplier(b -> b.operand(joinClass).anyInputs()) Review Comment: I left two design questions in Jira. I should have probably asked them sooner, but I only got time to think about them now. -- 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]
