spark BasicStatsPlanVisitor 源码
spark BasicStatsPlanVisitor 代码
文件路径:/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/statsEstimation/BasicStatsPlanVisitor.scala
/*
* 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.catalyst.plans.logical.statsEstimation
import org.apache.spark.sql.catalyst.plans.logical._
/**
* A [[LogicalPlanVisitor]] that computes the statistics for the cost-based optimizer.
*/
object BasicStatsPlanVisitor extends LogicalPlanVisitor[Statistics] {
/** Falls back to the estimation computed by [[SizeInBytesOnlyStatsPlanVisitor]]. */
private def fallback(p: LogicalPlan): Statistics = SizeInBytesOnlyStatsPlanVisitor.visit(p)
override def default(p: LogicalPlan): Statistics = p match {
case p: LeafNode => p.computeStats()
case _: LogicalPlan =>
val stats = p.children.map(_.stats)
val rowCount = if (stats.exists(_.rowCount.isEmpty)) {
None
} else {
Some(stats.map(_.rowCount.get).filter(_ > 0L).product)
}
Statistics(sizeInBytes = stats.map(_.sizeInBytes).filter(_ > 0L).product, rowCount = rowCount)
}
override def visitAggregate(p: Aggregate): Statistics = {
AggregateEstimation.estimate(p).getOrElse(fallback(p))
}
override def visitDistinct(p: Distinct): Statistics = {
val child = p.child
visitAggregate(Aggregate(child.output, child.output, child))
}
override def visitExcept(p: Except): Statistics = fallback(p)
override def visitExpand(p: Expand): Statistics = fallback(p)
override def visitFilter(p: Filter): Statistics = {
FilterEstimation(p).estimate.getOrElse(fallback(p))
}
override def visitGenerate(p: Generate): Statistics = default(p)
override def visitGlobalLimit(p: GlobalLimit): Statistics = fallback(p)
override def visitOffset(p: Offset): Statistics = fallback(p)
override def visitIntersect(p: Intersect): Statistics = {
val leftStats = p.left.stats
val rightStats = p.right.stats
val leftSize = leftStats.sizeInBytes
val rightSize = rightStats.sizeInBytes
if (leftSize < rightSize) {
Statistics(sizeInBytes = leftSize, rowCount = leftStats.rowCount)
} else {
Statistics(sizeInBytes = rightSize, rowCount = rightStats.rowCount)
}
}
override def visitJoin(p: Join): Statistics = {
JoinEstimation(p).estimate.getOrElse(fallback(p))
}
override def visitLocalLimit(p: LocalLimit): Statistics = fallback(p)
override def visitPivot(p: Pivot): Statistics = default(p)
override def visitProject(p: Project): Statistics = {
ProjectEstimation.estimate(p).getOrElse(fallback(p))
}
override def visitRepartition(p: Repartition): Statistics = fallback(p)
override def visitRepartitionByExpr(p: RepartitionByExpression): Statistics = fallback(p)
override def visitRebalancePartitions(p: RebalancePartitions): Statistics = fallback(p)
override def visitSample(p: Sample): Statistics = fallback(p)
override def visitScriptTransform(p: ScriptTransformation): Statistics = default(p)
override def visitUnion(p: Union): Statistics = {
UnionEstimation.estimate(p).getOrElse(fallback(p))
}
override def visitWindow(p: Window): Statistics = fallback(p)
override def visitSort(p: Sort): Statistics = fallback(p)
override def visitTail(p: Tail): Statistics = {
fallback(p)
}
override def visitWithCTE(p: WithCTE): Statistics = fallback(p)
}
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