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/*
* 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
import org.apache.spark.rdd.RDD
import org.apache.spark.sql.{execution, AnalysisException, Strategy}
import org.apache.spark.sql.catalyst.InternalRow
import org.apache.spark.sql.catalyst.encoders.RowEncoder
import org.apache.spark.sql.catalyst.expressions._
import org.apache.spark.sql.catalyst.planning._
import org.apache.spark.sql.catalyst.plans._
import org.apache.spark.sql.catalyst.plans.logical._
import org.apache.spark.sql.catalyst.plans.physical._
import org.apache.spark.sql.execution.columnar.{InMemoryRelation, InMemoryTableScanExec}
import org.apache.spark.sql.execution.command._
import org.apache.spark.sql.execution.exchange.ShuffleExchangeExec
import org.apache.spark.sql.execution.joins.{BuildLeft, BuildRight, BuildSide}
import org.apache.spark.sql.execution.streaming._
import org.apache.spark.sql.execution.streaming.sources.MemoryPlanV2
import org.apache.spark.sql.internal.SQLConf
import org.apache.spark.sql.streaming.StreamingQuery
import org.apache.spark.sql.types.StructType
/**
* Converts a logical plan into zero or more SparkPlans. This API is exposed for experimenting
* with the query planner and is not designed to be stable across spark releases. Developers
* writing libraries should instead consider using the stable APIs provided in
* [[org.apache.spark.sql.sources]]
*/
abstract class SparkStrategy extends GenericStrategy[SparkPlan] {
override protected def planLater(plan: LogicalPlan): SparkPlan = PlanLater(plan)
}
case class PlanLater(plan: LogicalPlan) extends LeafExecNode {
override def output: Seq[Attribute] = plan.output
protected override def doExecute(): RDD[InternalRow] = {
throw new UnsupportedOperationException()
}
}
abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
self: SparkPlanner =>
/**
* Plans special cases of limit operators.
*/
object SpecialLimits extends Strategy {
override def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case ReturnAnswer(rootPlan) => rootPlan match {
case Limit(IntegerLiteral(limit), Sort(order, true, child)) =>
TakeOrderedAndProjectExec(limit, order, child.output, planLater(child)) :: Nil
case Limit(IntegerLiteral(limit), Project(projectList, Sort(order, true, child))) =>
TakeOrderedAndProjectExec(limit, order, projectList, planLater(child)) :: Nil
case Limit(IntegerLiteral(limit), child) =>
// With whole stage codegen, Spark releases resources only when all the output data of the
// query plan are consumed. It's possible that `CollectLimitExec` only consumes a little
// data from child plan and finishes the query without releasing resources. Here we wrap
// the child plan with `LocalLimitExec`, to stop the processing of whole stage codegen and
// trigger the resource releasing work, after we consume `limit` rows.
CollectLimitExec(limit, LocalLimitExec(limit, planLater(child))) :: Nil
case other => planLater(other) :: Nil
}
case Limit(IntegerLiteral(limit), Sort(order, true, child)) =>
TakeOrderedAndProjectExec(limit, order, child.output, planLater(child)) :: Nil
case Limit(IntegerLiteral(limit), Project(projectList, Sort(order, true, child))) =>
TakeOrderedAndProjectExec(limit, order, projectList, planLater(child)) :: Nil
case _ => Nil
}
}
/**
* Select the proper physical plan for join based on joining keys and size of logical plan.
*
* At first, uses the [[ExtractEquiJoinKeys]] pattern to find joins where at least some of the
* predicates can be evaluated by matching join keys. If found, join implementations are chosen
* with the following precedence:
*
* - Broadcast hash join (BHJ):
* BHJ is not supported for full outer join. For right outer join, we only can broadcast the
* left side. For left outer, left semi, left anti and the internal join type ExistenceJoin,
* we only can broadcast the right side. For inner like join, we can broadcast both sides.
* Normally, BHJ can perform faster than the other join algorithms when the broadcast side is
* small. However, broadcasting tables is a network-intensive operation. It could cause OOM
* or perform worse than the other join algorithms, especially when the build/broadcast side
* is big.
*
* For the supported cases, users can specify the broadcast hint (e.g. the user applied the
* [[org.apache.spark.sql.functions.broadcast()]] function to a DataFrame) and session-based
* [[SQLConf.AUTO_BROADCASTJOIN_THRESHOLD]] threshold to adjust whether BHJ is used and
* which join side is broadcast.
*
* 1) Broadcast the join side with the broadcast hint, even if the size is larger than
* [[SQLConf.AUTO_BROADCASTJOIN_THRESHOLD]]. If both sides have the hint (only when the type
* is inner like join), the side with a smaller estimated physical size will be broadcast.
* 2) Respect the [[SQLConf.AUTO_BROADCASTJOIN_THRESHOLD]] threshold and broadcast the side
* whose estimated physical size is smaller than the threshold. If both sides are below the
* threshold, broadcast the smaller side. If neither is smaller, BHJ is not used.
*
* - Shuffle hash join: if the average size of a single partition is small enough to build a hash
* table.
*
* - Sort merge: if the matching join keys are sortable.
*
* If there is no joining keys, Join implementations are chosen with the following precedence:
* - BroadcastNestedLoopJoin (BNLJ):
* BNLJ supports all the join types but the impl is OPTIMIZED for the following scenarios:
* For right outer join, the left side is broadcast. For left outer, left semi, left anti
* and the internal join type ExistenceJoin, the right side is broadcast. For inner like
* joins, either side is broadcast.
*
* Like BHJ, users still can specify the broadcast hint and session-based
* [[SQLConf.AUTO_BROADCASTJOIN_THRESHOLD]] threshold to impact which side is broadcast.
*
* 1) Broadcast the join side with the broadcast hint, even if the size is larger than
* [[SQLConf.AUTO_BROADCASTJOIN_THRESHOLD]]. If both sides have the hint (i.e., just for
* inner-like join), the side with a smaller estimated physical size will be broadcast.
* 2) Respect the [[SQLConf.AUTO_BROADCASTJOIN_THRESHOLD]] threshold and broadcast the side
* whose estimated physical size is smaller than the threshold. If both sides are below the
* threshold, broadcast the smaller side. If neither is smaller, BNLJ is not used.
*
* - CartesianProduct: for inner like join, CartesianProduct is the fallback option.
*
* - BroadcastNestedLoopJoin (BNLJ):
* For the other join types, BNLJ is the fallback option. Here, we just pick the broadcast
* side with the broadcast hint. If neither side has a hint, we broadcast the side with
* the smaller estimated physical size.
*/
object JoinSelection extends Strategy with PredicateHelper {
/**
* Matches a plan whose output should be small enough to be used in broadcast join.
*/
private def canBroadcast(plan: LogicalPlan): Boolean = {
plan.stats.sizeInBytes >= 0 && plan.stats.sizeInBytes <= conf.autoBroadcastJoinThreshold
}
/**
* Matches a plan whose single partition should be small enough to build a hash table.
*
* Note: this assume that the number of partition is fixed, requires additional work if it's
* dynamic.
*/
private def canBuildLocalHashMap(plan: LogicalPlan): Boolean = {
plan.stats.sizeInBytes < conf.autoBroadcastJoinThreshold * conf.numShufflePartitions
}
/**
* Returns whether plan a is much smaller (3X) than plan b.
*
* The cost to build hash map is higher than sorting, we should only build hash map on a table
* that is much smaller than other one. Since we does not have the statistic for number of rows,
* use the size of bytes here as estimation.
*/
private def muchSmaller(a: LogicalPlan, b: LogicalPlan): Boolean = {
a.stats.sizeInBytes * 3 <= b.stats.sizeInBytes
}
private def canBuildRight(joinType: JoinType): Boolean = joinType match {
case _: InnerLike | LeftOuter | LeftSemi | LeftAnti | _: ExistenceJoin => true
case _ => false
}
private def canBuildLeft(joinType: JoinType): Boolean = joinType match {
case _: InnerLike | RightOuter => true
case _ => false
}
private def broadcastSide(
canBuildLeft: Boolean,
canBuildRight: Boolean,
left: LogicalPlan,
right: LogicalPlan): BuildSide = {
def smallerSide =
if (right.stats.sizeInBytes <= left.stats.sizeInBytes) BuildRight else BuildLeft
if (canBuildRight && canBuildLeft) {
// Broadcast smaller side base on its estimated physical size
// if both sides have broadcast hint
smallerSide
} else if (canBuildRight) {
BuildRight
} else if (canBuildLeft) {
BuildLeft
} else {
// for the last default broadcast nested loop join
smallerSide
}
}
private def canBroadcastByHints(joinType: JoinType, left: LogicalPlan, right: LogicalPlan)
: Boolean = {
val buildLeft = canBuildLeft(joinType) && left.stats.hints.broadcast
val buildRight = canBuildRight(joinType) && right.stats.hints.broadcast
buildLeft || buildRight
}
private def broadcastSideByHints(joinType: JoinType, left: LogicalPlan, right: LogicalPlan)
: BuildSide = {
val buildLeft = canBuildLeft(joinType) && left.stats.hints.broadcast
val buildRight = canBuildRight(joinType) && right.stats.hints.broadcast
broadcastSide(buildLeft, buildRight, left, right)
}
private def canBroadcastBySizes(joinType: JoinType, left: LogicalPlan, right: LogicalPlan)
: Boolean = {
val buildLeft = canBuildLeft(joinType) && canBroadcast(left)
val buildRight = canBuildRight(joinType) && canBroadcast(right)
buildLeft || buildRight
}
private def broadcastSideBySizes(joinType: JoinType, left: LogicalPlan, right: LogicalPlan)
: BuildSide = {
val buildLeft = canBuildLeft(joinType) && canBroadcast(left)
val buildRight = canBuildRight(joinType) && canBroadcast(right)
broadcastSide(buildLeft, buildRight, left, right)
}
def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
// --- BroadcastHashJoin --------------------------------------------------------------------
// broadcast hints were specified
case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, left, right)
if canBroadcastByHints(joinType, left, right) =>
val buildSide = broadcastSideByHints(joinType, left, right)
Seq(joins.BroadcastHashJoinExec(
leftKeys, rightKeys, joinType, buildSide, condition, planLater(left), planLater(right)))
// broadcast hints were not specified, so need to infer it from size and configuration.
case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, left, right)
if canBroadcastBySizes(joinType, left, right) =>
val buildSide = broadcastSideBySizes(joinType, left, right)
Seq(joins.BroadcastHashJoinExec(
leftKeys, rightKeys, joinType, buildSide, condition, planLater(left), planLater(right)))
// --- ShuffledHashJoin ---------------------------------------------------------------------
case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, left, right)
if !conf.preferSortMergeJoin && canBuildRight(joinType) && canBuildLocalHashMap(right)
&& muchSmaller(right, left) ||
!RowOrdering.isOrderable(leftKeys) =>
Seq(joins.ShuffledHashJoinExec(
leftKeys, rightKeys, joinType, BuildRight, condition, planLater(left), planLater(right)))
case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, left, right)
if !conf.preferSortMergeJoin && canBuildLeft(joinType) && canBuildLocalHashMap(left)
&& muchSmaller(left, right) ||
!RowOrdering.isOrderable(leftKeys) =>
Seq(joins.ShuffledHashJoinExec(
leftKeys, rightKeys, joinType, BuildLeft, condition, planLater(left), planLater(right)))
// --- SortMergeJoin ------------------------------------------------------------
case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, left, right)
if RowOrdering.isOrderable(leftKeys) =>
joins.SortMergeJoinExec(
leftKeys, rightKeys, joinType, condition, planLater(left), planLater(right)) :: Nil
// --- Without joining keys ------------------------------------------------------------
// Pick BroadcastNestedLoopJoin if one side could be broadcast
case j @ logical.Join(left, right, joinType, condition)
if canBroadcastByHints(joinType, left, right) =>
val buildSide = broadcastSideByHints(joinType, left, right)
joins.BroadcastNestedLoopJoinExec(
planLater(left), planLater(right), buildSide, joinType, condition) :: Nil
case j @ logical.Join(left, right, joinType, condition)
if canBroadcastBySizes(joinType, left, right) =>
val buildSide = broadcastSideBySizes(joinType, left, right)
joins.BroadcastNestedLoopJoinExec(
planLater(left), planLater(right), buildSide, joinType, condition) :: Nil
// Pick CartesianProduct for InnerJoin
case logical.Join(left, right, _: InnerLike, condition) =>
joins.CartesianProductExec(planLater(left), planLater(right), condition) :: Nil
case logical.Join(left, right, joinType, condition) =>
val buildSide = broadcastSide(
left.stats.hints.broadcast, right.stats.hints.broadcast, left, right)
// This join could be very slow or OOM
joins.BroadcastNestedLoopJoinExec(
planLater(left), planLater(right), buildSide, joinType, condition) :: Nil
// --- Cases where this strategy does not apply ---------------------------------------------
case _ => Nil
}
}
/**
* Used to plan streaming aggregation queries that are computed incrementally as part of a
* [[StreamingQuery]]. Currently this rule is injected into the planner
* on-demand, only when planning in a [[org.apache.spark.sql.execution.streaming.StreamExecution]]
*/
object StatefulAggregationStrategy extends Strategy {
override def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case _ if !plan.isStreaming => Nil
case EventTimeWatermark(columnName, delay, child) =>
EventTimeWatermarkExec(columnName, delay, planLater(child)) :: Nil
case PhysicalAggregation(
namedGroupingExpressions, aggregateExpressions, rewrittenResultExpressions, child) =>
aggregate.AggUtils.planStreamingAggregation(
namedGroupingExpressions,
aggregateExpressions,
rewrittenResultExpressions,
planLater(child))
case _ => Nil
}
}
/**
* Used to plan the streaming deduplicate operator.
*/
object StreamingDeduplicationStrategy extends Strategy {
override def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case Deduplicate(keys, child) if child.isStreaming =>
StreamingDeduplicateExec(keys, planLater(child)) :: Nil
case _ => Nil
}
}
object StreamingJoinStrategy extends Strategy {
override def apply(plan: LogicalPlan): Seq[SparkPlan] = {
plan match {
case ExtractEquiJoinKeys(joinType, leftKeys, rightKeys, condition, left, right)
if left.isStreaming && right.isStreaming =>
new StreamingSymmetricHashJoinExec(
leftKeys, rightKeys, joinType, condition, planLater(left), planLater(right)) :: Nil
case Join(left, right, _, _) if left.isStreaming && right.isStreaming =>
throw new AnalysisException(
"Stream stream joins without equality predicate is not supported", plan = Some(plan))
case _ => Nil
}
}
}
/**
* Used to plan the aggregate operator for expressions based on the AggregateFunction2 interface.
*/
object Aggregation extends Strategy {
def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case PhysicalAggregation(
groupingExpressions, aggregateExpressions, resultExpressions, child) =>
val (functionsWithDistinct, functionsWithoutDistinct) =
aggregateExpressions.partition(_.isDistinct)
if (functionsWithDistinct.map(_.aggregateFunction.children).distinct.length > 1) {
// This is a sanity check. We should not reach here when we have multiple distinct
// column sets. Our MultipleDistinctRewriter should take care this case.
sys.error("You hit a query analyzer bug. Please report your query to " +
"Spark user mailing list.")
}
val aggregateOperator =
if (functionsWithDistinct.isEmpty) {
aggregate.AggUtils.planAggregateWithoutDistinct(
groupingExpressions,
aggregateExpressions,
resultExpressions,
planLater(child))
} else {
aggregate.AggUtils.planAggregateWithOneDistinct(
groupingExpressions,
functionsWithDistinct,
functionsWithoutDistinct,
resultExpressions,
planLater(child))
}
aggregateOperator
case _ => Nil
}
}
protected lazy val singleRowRdd = sparkContext.parallelize(Seq(InternalRow()), 1)
object InMemoryScans extends Strategy {
def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case PhysicalOperation(projectList, filters, mem: InMemoryRelation) =>
pruneFilterProject(
projectList,
filters,
identity[Seq[Expression]], // All filters still need to be evaluated.
InMemoryTableScanExec(_, filters, mem)) :: Nil
case _ => Nil
}
}
/**
* This strategy is just for explaining `Dataset/DataFrame` created by `spark.readStream`.
* It won't affect the execution, because `StreamingRelation` will be replaced with
* `StreamingExecutionRelation` in `StreamingQueryManager` and `StreamingExecutionRelation` will
* be replaced with the real relation using the `Source` in `StreamExecution`.
*/
object StreamingRelationStrategy extends Strategy {
def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case s: StreamingRelation =>
StreamingRelationExec(s.sourceName, s.output) :: Nil
case s: StreamingExecutionRelation =>
StreamingRelationExec(s.toString, s.output) :: Nil
case s: StreamingRelationV2 =>
StreamingRelationExec(s.sourceName, s.output) :: Nil
case _ => Nil
}
}
/**
* Strategy to convert [[FlatMapGroupsWithState]] logical operator to physical operator
* in streaming plans. Conversion for batch plans is handled by [[BasicOperators]].
*/
object FlatMapGroupsWithStateStrategy extends Strategy {
override def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case FlatMapGroupsWithState(
func, keyDeser, valueDeser, groupAttr, dataAttr, outputAttr, stateEnc, outputMode, _,
timeout, child) =>
val execPlan = FlatMapGroupsWithStateExec(
func, keyDeser, valueDeser, groupAttr, dataAttr, outputAttr, None, stateEnc, outputMode,
timeout, batchTimestampMs = None, eventTimeWatermark = None, planLater(child))
execPlan :: Nil
case _ =>
Nil
}
}
// Can we automate these 'pass through' operations?
object BasicOperators extends Strategy {
def apply(plan: LogicalPlan): Seq[SparkPlan] = plan match {
case d: DataWritingCommand => DataWritingCommandExec(d, planLater(d.query)) :: Nil
case r: RunnableCommand => ExecutedCommandExec(r) :: Nil
case MemoryPlan(sink, output) =>
val encoder = RowEncoder(sink.schema)
LocalTableScanExec(output, sink.allData.map(r => encoder.toRow(r).copy())) :: Nil
case MemoryPlanV2(sink, output) =>
val encoder = RowEncoder(StructType.fromAttributes(output))
LocalTableScanExec(output, sink.allData.map(r => encoder.toRow(r).copy())) :: Nil
case logical.Distinct(child) =>
throw new IllegalStateException(
"logical distinct operator should have been replaced by aggregate in the optimizer")
case logical.Intersect(left, right) =>
throw new IllegalStateException(
"logical intersect operator should have been replaced by semi-join in the optimizer")
case logical.Except(left, right) =>
throw new IllegalStateException(
"logical except operator should have been replaced by anti-join in the optimizer")
case logical.DeserializeToObject(deserializer, objAttr, child) =>
execution.DeserializeToObjectExec(deserializer, objAttr, planLater(child)) :: Nil
case logical.SerializeFromObject(serializer, child) =>
execution.SerializeFromObjectExec(serializer, planLater(child)) :: Nil
case logical.MapPartitions(f, objAttr, child) =>
execution.MapPartitionsExec(f, objAttr, planLater(child)) :: Nil
case logical.MapPartitionsInR(f, p, b, is, os, objAttr, child) =>
execution.MapPartitionsExec(
execution.r.MapPartitionsRWrapper(f, p, b, is, os), objAttr, planLater(child)) :: Nil
case logical.FlatMapGroupsInR(f, p, b, is, os, key, value, grouping, data, objAttr, child) =>
execution.FlatMapGroupsInRExec(f, p, b, is, os, key, value, grouping,
data, objAttr, planLater(child)) :: Nil
case logical.FlatMapGroupsInPandas(grouping, func, output, child) =>
execution.python.FlatMapGroupsInPandasExec(grouping, func, output, planLater(child)) :: Nil
case logical.MapElements(f, _, _, objAttr, child) =>
execution.MapElementsExec(f, objAttr, planLater(child)) :: Nil
case logical.AppendColumns(f, _, _, in, out, child) =>
execution.AppendColumnsExec(f, in, out, planLater(child)) :: Nil
case logical.AppendColumnsWithObject(f, childSer, newSer, child) =>
execution.AppendColumnsWithObjectExec(f, childSer, newSer, planLater(child)) :: Nil
case logical.MapGroups(f, key, value, grouping, data, objAttr, child) =>
execution.MapGroupsExec(f, key, value, grouping, data, objAttr, planLater(child)) :: Nil
case logical.FlatMapGroupsWithState(
f, key, value, grouping, data, output, _, _, _, timeout, child) =>
execution.MapGroupsExec(
f, key, value, grouping, data, output, timeout, planLater(child)) :: Nil
case logical.CoGroup(f, key, lObj, rObj, lGroup, rGroup, lAttr, rAttr, oAttr, left, right) =>
execution.CoGroupExec(
f, key, lObj, rObj, lGroup, rGroup, lAttr, rAttr, oAttr,
planLater(left), planLater(right)) :: Nil
case logical.Repartition(numPartitions, shuffle, child) =>
if (shuffle) {
ShuffleExchangeExec(RoundRobinPartitioning(numPartitions), planLater(child)) :: Nil
} else {
execution.CoalesceExec(numPartitions, planLater(child)) :: Nil
}
case logical.Sort(sortExprs, global, child) =>
execution.SortExec(sortExprs, global, planLater(child)) :: Nil
case logical.Project(projectList, child) =>
execution.ProjectExec(projectList, planLater(child)) :: Nil
case logical.Filter(condition, child) =>
execution.FilterExec(condition, planLater(child)) :: Nil
case f: logical.TypedFilter =>
execution.FilterExec(f.typedCondition(f.deserializer), planLater(f.child)) :: Nil
case e @ logical.Expand(_, _, child) =>
execution.ExpandExec(e.projections, e.output, planLater(child)) :: Nil
case logical.Window(windowExprs, partitionSpec, orderSpec, child) =>
execution.window.WindowExec(windowExprs, partitionSpec, orderSpec, planLater(child)) :: Nil
case logical.Sample(lb, ub, withReplacement, seed, child) =>
execution.SampleExec(lb, ub, withReplacement, seed, planLater(child)) :: Nil
case logical.LocalRelation(output, data, _) =>
LocalTableScanExec(output, data) :: Nil
case logical.LocalLimit(IntegerLiteral(limit), child) =>
execution.LocalLimitExec(limit, planLater(child)) :: Nil
case logical.GlobalLimit(IntegerLiteral(limit), child) =>
execution.GlobalLimitExec(limit, planLater(child)) :: Nil
case logical.Union(unionChildren) =>
execution.UnionExec(unionChildren.map(planLater)) :: Nil
case g @ logical.Generate(generator, _, outer, _, _, child) =>
execution.GenerateExec(
generator, g.requiredChildOutput, outer,
g.qualifiedGeneratorOutput, planLater(child)) :: Nil
case _: logical.OneRowRelation =>
execution.RDDScanExec(Nil, singleRowRdd, "OneRowRelation") :: Nil
case r: logical.Range =>
execution.RangeExec(r) :: Nil
case r: logical.RepartitionByExpression =>
exchange.ShuffleExchangeExec(r.partitioning, planLater(r.child)) :: Nil
case ExternalRDD(outputObjAttr, rdd) => ExternalRDDScanExec(outputObjAttr, rdd) :: Nil
case r: LogicalRDD =>
RDDScanExec(r.output, r.rdd, "ExistingRDD", r.outputPartitioning, r.outputOrdering) :: Nil
case h: ResolvedHint => planLater(h.child) :: Nil
case _ => Nil
}
}
}
