org.apache.spark.sql.catalyst.plans.logical.statsEstimation.LogicalPlanStats.scala Maven / Gradle / Ivy
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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.catalyst.plans.logical.statsEstimation
import org.apache.spark.sql.catalyst.plans.logical._
/**
* A trait to add statistics propagation to [[LogicalPlan]].
*/
trait LogicalPlanStats { self: LogicalPlan =>
/**
* Returns the estimated statistics for the current logical plan node. Under the hood, this
* method caches the return value, which is computed based on the configuration passed in the
* first time. If the configuration changes, the cache can be invalidated by calling
* [[invalidateStatsCache()]].
*/
def stats: Statistics = statsCache.getOrElse {
if (conf.cboEnabled) {
statsCache = Option(BasicStatsPlanVisitor.visit(self))
} else {
statsCache = Option(SizeInBytesOnlyStatsPlanVisitor.visit(self))
}
statsCache.get
}
/** A cache for the estimated statistics, such that it will only be computed once. */
protected var statsCache: Option[Statistics] = None
/** Invalidates the stats cache. See [[stats]] for more information. */
final def invalidateStatsCache(): Unit = {
statsCache = None
children.foreach(_.invalidateStatsCache())
}
}