xiedeyantu commented on code in PR #4280: URL: https://github.com/apache/calcite/pull/4280#discussion_r2039076878
########## core/src/main/java/org/apache/calcite/rel/rules/JoinConditionOrExpansionRule.java: ########## @@ -0,0 +1,401 @@ +/* + * 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.RelNode; +import org.apache.calcite.rel.core.Join; +import org.apache.calcite.rel.core.JoinRelType; +import org.apache.calcite.rex.RexBuilder; +import org.apache.calcite.rex.RexCall; +import org.apache.calcite.rex.RexInputRef; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.tools.RelBuilder; + +import org.checkerframework.checker.nullness.qual.Nullable; +import org.immutables.value.Value; + +import java.util.ArrayList; +import java.util.List; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +/** + * Planner rule that matches a + * {@link org.apache.calcite.rel.core.Join} + * and expands OR clauses in join conditions. + * + * <p>This rule expands OR conditions in join clauses into + * multiple separate join conditions, allowing the optimizer + * to handle these conditions more efficiently. + * + * <p>The following is an example of inner join, + * and other examples for other kinds of joins + * can be found in the code below. + * + * <p>Project[*] + * └── Join[OR(t1.id=t2.id, t1.age=t2.age), inner] + * ├── TableScan[t1] + * └── TableScan[t2] + * + * <p>into + * + * <p>Project[*] + * └── UnionAll + * ├── Join[t1.id=t2.id, inner] + * │ ├── TableScan[t1] + * │ └── TableScan[t2] + * └── Join[t1.age=t2.age AND t1.id≠t2.id, inner] + * ├─── TableScan[t1] + * └─── TableScan[t2] + * + */ +@Value.Enclosing +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(); + + RelNode converted; + switch (join.getJoinType()) { + case INNER: + converted = expandInnerJoin(join, relBuilder); + break; + case ANTI: + converted = expandAntiJoin(join, relBuilder); + break; + case LEFT: + converted = expandLeftOrRightJoin(join, true, relBuilder); + break; + case RIGHT: + converted = expandLeftOrRightJoin(join, false, relBuilder); + break; + case FULL: + converted = expandFullJoin(join, relBuilder); + break; + default: + return; + } + + if (converted == null) { + return; + } + call.transformTo(converted); + } + + private boolean skip(Join join) { + List<RexNode> orConds = RelOptUtil.disjunctions(join.getCondition()); + return orConds.size() <= 1; + } + + private List<RexNode> splitCond(Join join) { + final RexBuilder builder = join.getCluster().getRexBuilder(); + final List<RexNode> orConds = RelOptUtil.disjunctions(join.getCondition()); + final int leftFieldCount = join.getLeft().getRowType().getFieldCount(); + + final List<RexNode> result = new ArrayList<>(); + final List<RexNode> otherBuffer = new ArrayList<>(); + + for (RexNode cond : orConds) { + if (isUsefulCond(cond, leftFieldCount)) { + if (!otherBuffer.isEmpty()) { + result.add(RexUtil.composeDisjunction(builder, otherBuffer)); + otherBuffer.clear(); + } + result.add(cond); + } else { + otherBuffer.add(cond); + } + } + + if (!otherBuffer.isEmpty()) { + result.add(RexUtil.composeDisjunction(builder, otherBuffer)); + } + + return result; + } + + private boolean isUsefulCond(RexNode node, int leftFieldCount) { + if (!(node instanceof RexCall)) { + return false; + } + + RexCall call = (RexCall) node; + SqlKind kind = call.getKind(); + switch (kind) { + case EQUALS: + case IS_NOT_DISTINCT_FROM: + RexNode left = call.getOperands().get(0); Review Comment: For example, it also includes is not distinct from, and the cast you mentioned, maybe it is not very appropriate to use whether it contains equal conditions, or is there any better name you can recommend? -- 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: commits-unsubscr...@calcite.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
