diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala index 01fbe5b7c2c03aa4b018e40e44cb2e4d67f3485c..86a8770715600e6f3691ae7ada5e8109099d79fe 100644 --- a/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala +++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala @@ -39,9 +39,10 @@ case class CollectLimitExec(limit: Int, child: SparkPlan) extends UnaryExecNode override def executeCollect(): Array[InternalRow] = child.executeTake(limit) private val serializer: Serializer = new UnsafeRowSerializer(child.output.size) protected override def doExecute(): RDD[InternalRow] = { + val locallyLimited = child.execute().mapPartitionsInternal(_.take(limit)) val shuffled = new ShuffledRowRDD( ShuffleExchange.prepareShuffleDependency( - child.execute(), child.output, SinglePartition, serializer)) + locallyLimited, child.output, SinglePartition, serializer)) shuffled.mapPartitionsInternal(_.take(limit)) } } diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala index eac266cba55b8470b9d36a9d4603306b4db070aa..a2164f9ae3d3ed3010d3f8625bbb5326637ee418 100644 --- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala +++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala @@ -2661,4 +2661,13 @@ class SQLQuerySuite extends QueryTest with SharedSQLContext { data.selectExpr("`part.col1`", "`col.1`")) } } + + test("SPARK-17515: CollectLimit.execute() should perform per-partition limits") { + val numRecordsRead = spark.sparkContext.longAccumulator + spark.range(1, 100, 1, numPartitions = 10).map { x => + numRecordsRead.add(1) + x + }.limit(1).queryExecution.toRdd.count() + assert(numRecordsRead.value === 10) + } }