hvanhovell commented on a change in pull request #24706: [SPARK-23128][SQL] A new approach to do adaptive execution in Spark SQL URL: https://github.com/apache/spark/pull/24706#discussion_r293116306
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/adaptive/QueryStageExec.scala ########## @@ -0,0 +1,210 @@ +/* + * 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.adaptive + +import scala.concurrent.Future + +import org.apache.spark.{FutureAction, MapOutputStatistics} +import org.apache.spark.broadcast.Broadcast +import org.apache.spark.rdd.RDD +import org.apache.spark.sql.catalyst.InternalRow +import org.apache.spark.sql.catalyst.expressions._ +import org.apache.spark.sql.catalyst.plans.logical.Statistics +import org.apache.spark.sql.catalyst.plans.physical.Partitioning +import org.apache.spark.sql.execution._ +import org.apache.spark.sql.execution.exchange._ + + +/** + * A query stage is an independent subgraph of the query plan. Query stage materializes its output + * before proceeding with further operators of the query plan. The data statistics of the + * materialized output can be used to optimize subsequent query stages. + * + * There are 2 kinds of query stages: + * 1. Shuffle query stage. This stage materializes its output to shuffle files, and Spark launches + * another job to execute the further operators. + * 2. Broadcast query stage. This stage materializes its output to an array in driver JVM. Spark + * broadcasts the array before executing the further operators. + */ +abstract class QueryStageExec extends LeafExecNode { + + /** + * An id of this query stage which is unique in the entire query plan. + */ + def id: Int Review comment: NIT: this really should be a `val`, since it is not supposed to change. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
