twalthr commented on code in PR #26966: URL: https://github.com/apache/flink/pull/26966#discussion_r2330363054
########## flink-table/flink-table-planner/src/main/java/org/apache/calcite/rel/rules/MultiJoin.java: ########## @@ -0,0 +1,306 @@ +/* + * 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 com.google.common.collect.ImmutableList; +import com.google.common.collect.ImmutableMap; +import com.google.common.collect.Lists; +import org.apache.calcite.linq4j.Ord; +import org.apache.calcite.plan.Convention; +import org.apache.calcite.plan.RelOptCluster; +import org.apache.calcite.plan.RelTraitSet; +import org.apache.calcite.rel.AbstractRelNode; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.RelWriter; +import org.apache.calcite.rel.core.JoinRelType; +import org.apache.calcite.rel.hint.RelHint; +import org.apache.calcite.rel.type.RelDataType; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.util.ImmutableBitSet; +import org.apache.calcite.util.ImmutableIntList; +import org.apache.calcite.util.ImmutableNullableList; +import org.checkerframework.checker.nullness.qual.Nullable; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +import static java.util.Objects.requireNonNull; + +/** + * A MultiJoin represents a join of N inputs, whereas regular Joins represent strictly binary joins. Review Comment: I agree with David here. More context is required in the JavaDoc of this class. If we copy Calcite classes, the corresponding CALCITE Jira ticket should be linked and the modification clearly indicated by `FLINK MODIFICATION BEGIN/END` like in other Calcite classes. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
