alamb commented on issue #5523: URL: https://github.com/apache/arrow-rs/issues/5523#issuecomment-2429364040
An important goal of this ticket, mentioned by @tustvold in https://github.com/apache/arrow-rs/issues/6454#issuecomment-2402118020, is that evaluating predicates in `ArrowFilter` (aka pushed down predicates) is never worse than decoding the columns first and then filtering them with the `filter` kernel If we are able to achieve this goal, it would mean that query engines like DataFusion could push all predicates down into the predicate reader always. At the moment, since it sometimes faster to apply filters after reading columns than it is via `ArrowPredicate` sometimes queries get slower when all predicates are pushed down. When it makes sense to push predicates down depends on their actual selectivity, which is only known for sure during evaluation Thus, I agree with the conclusion that implementing adaptivity in the lowest level scan will achieve the goal -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
