KnownSizeEstimation¶

KnownSizeEstimation is an abstraction of size estimators that can give a more precise size estimation.

Contract¶

Estimated Size¶

estimatedSize: Long

estimatedSize is used when:

• SizeEstimator is requested to visitSingleObject
• BroadcastExchangeExec physical operator is requested for relationFuture
• BroadcastHashJoinExec physical operator is executed
• ShuffledHashJoinExec physical operator is requested to buildHashedRelation

Implementations¶

• HashedRelation