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EstimationUtils

EstimationUtils is...FIXME

=== [[getOutputSize]] getOutputSize Method

[source, scala]

getOutputSize( attributes: Seq[Attribute], outputRowCount: BigInt, attrStats: AttributeMap[ColumnStat] = AttributeMap(Nil)): BigInt


getOutputSize...FIXME

NOTE: getOutputSize is used when...FIXME

=== [[nullColumnStat]] nullColumnStat Method

[source, scala]

nullColumnStat(dataType: DataType, rowCount: BigInt): ColumnStat

nullColumnStat...FIXME

NOTE: nullColumnStat is used exclusively when JoinEstimation is requested to estimateInnerOuterJoin for LeftOuter and RightOuter joins.

=== [[rowCountsExist]] Checking Availability of Row Count Statistic -- rowCountsExist Method

[source, scala]

rowCountsExist(plans: LogicalPlan*): Boolean

rowCountsExist is positive (i.e. true) when every logical plan (in the input plans) has estimated number of rows (aka row count) statistic computed.

Otherwise, rowCountsExist is negative (i.e. false).

NOTE: rowCountsExist uses LogicalPlanStats to access the estimated statistics and query hints of a logical plan.

rowCountsExist is used when:


Last update: 2020-09-08