dbaliafroozeh commented on a change in pull request #28885: URL: https://github.com/apache/spark/pull/28885#discussion_r446698444
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/reuse/Reuse.scala ########## @@ -0,0 +1,90 @@ +/* + * 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.spark.sql.execution.reuse + +import scala.collection.mutable.Map + +import org.apache.spark.sql.catalyst.rules.Rule +import org.apache.spark.sql.execution.{BaseSubqueryExec, ExecSubqueryExpression, ReusedSubqueryExec, SparkPlan} +import org.apache.spark.sql.execution.exchange.{Exchange, ReusedExchangeExec} +import org.apache.spark.sql.internal.SQLConf +import org.apache.spark.sql.types.StructType + +/** + * Find out duplicated exchanges and subqueries in the whole spark plan including subqueries, then + * use the same exhange or subquery for all the references. + */ +case class ReuseExchangeAndSubquery(conf: SQLConf) extends Rule[SparkPlan] { + + private class ReuseCache[T <: SparkPlan] { Review comment: I like this new abstraction, just two nitpicky comments: - This is not really a cache IMO, in a sense that we need to hold on to all the values, it's more a memo table. How about renaming it to `ReuseMap`? or something in this line? - Can we move this class somewhere else? I know it's being used only here, but I think it'll be great to use this anytime we wanna lookup something with canonicalized forms. If you agree to move it to a util package, let's also make the type upperbound `QueryPlan` so that we can use it for other node types. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
