org.apache.spark.sql.catalyst.plans.LeftOuter Scala Examples

The following examples show how to use org.apache.spark.sql.catalyst.plans.LeftOuter. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example.
Example 1
Source File: ShuffledHashOuterJoin.scala    From spark1.52   with Apache License 2.0 5 votes vote down vote up 
package org.apache.spark.sql.execution.joins

import scala.collection.JavaConversions._

import org.apache.spark.annotation.DeveloperApi
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.physical._
import org.apache.spark.sql.catalyst.plans.{FullOuter, JoinType, LeftOuter, RightOuter}
import org.apache.spark.sql.execution.{BinaryNode, SparkPlan}
import org.apache.spark.sql.execution.metric.SQLMetrics


@DeveloperApi
case class ShuffledHashOuterJoin(
    leftKeys: Seq[Expression],
    rightKeys: Seq[Expression],
    joinType: JoinType,
    condition: Option[Expression],
    left: SparkPlan,
    right: SparkPlan) extends BinaryNode with HashOuterJoin {

  override private[sql] lazy val metrics = Map(
    "numLeftRows" -> SQLMetrics.createLongMetric(sparkContext, "number of left rows"),
    "numRightRows" -> SQLMetrics.createLongMetric(sparkContext, "number of right rows"),
    "numOutputRows" -> SQLMetrics.createLongMetric(sparkContext, "number of output rows"))

  override def requiredChildDistribution: Seq[Distribution] =
    ClusteredDistribution(leftKeys) :: ClusteredDistribution(rightKeys) :: Nil

  override def outputPartitioning: Partitioning = joinType match {
    case LeftOuter => left.outputPartitioning
    case RightOuter => right.outputPartitioning
    case FullOuter => UnknownPartitioning(left.outputPartitioning.numPartitions)
    case x =>
      throw new IllegalArgumentException(s"HashOuterJoin should not take $x as the JoinType")
  }

  protected override def doExecute(): RDD[InternalRow] = {
    val numLeftRows = longMetric("numLeftRows")
    val numRightRows = longMetric("numRightRows")
    val numOutputRows = longMetric("numOutputRows")

    val joinedRow = new JoinedRow()
    left.execute().zipPartitions(right.execute()) { (leftIter, rightIter) =>
      // TODO this probably can be replaced by external sort (sort merged join?)
      joinType match {
        case LeftOuter =>
          val hashed = HashedRelation(rightIter, numRightRows, buildKeyGenerator)
          val keyGenerator = streamedKeyGenerator
          val resultProj = resultProjection
          leftIter.flatMap( currentRow => {
            numLeftRows += 1
            val rowKey = keyGenerator(currentRow)
            joinedRow.withLeft(currentRow)
            leftOuterIterator(rowKey, joinedRow, hashed.get(rowKey), resultProj, numOutputRows)
          })

        case RightOuter =>
          val hashed = HashedRelation(leftIter, numLeftRows, buildKeyGenerator)
          val keyGenerator = streamedKeyGenerator
          val resultProj = resultProjection
          rightIter.flatMap ( currentRow => {
            numRightRows += 1
            val rowKey = keyGenerator(currentRow)
            joinedRow.withRight(currentRow)
            rightOuterIterator(rowKey, hashed.get(rowKey), joinedRow, resultProj, numOutputRows)
          })

        case FullOuter =>
          // TODO(davies): use UnsafeRow
          val leftHashTable =
            buildHashTable(leftIter, numLeftRows, newProjection(leftKeys, left.output))
          val rightHashTable =
            buildHashTable(rightIter, numRightRows, newProjection(rightKeys, right.output))
          (leftHashTable.keySet ++ rightHashTable.keySet).iterator.flatMap { key =>
            fullOuterIterator(key,
              leftHashTable.getOrElse(key, EMPTY_LIST),
              rightHashTable.getOrElse(key, EMPTY_LIST),
              joinedRow,
              numOutputRows)
          }

        case x =>
          throw new IllegalArgumentException(
            s"ShuffledHashOuterJoin should not take $x as the JoinType")
      }
    }
  }
}