zanmato1984 commented on PR #50423: URL: https://github.com/apache/arrow/pull/50423#issuecomment-4933130148
@pitrou Although the current Grouper API contract does not explicitly specify the ordering of GetUniques(), the existing tests strongly suggest that it is expected to preserve first-seen order. If we agree that this should be part of the contract, then this issue should probably be treated as a FastGrouperImpl bug, and the pivot_wider fix would not be strictly necessary. That said, keeping the explicit mapping here as a safeguard seems reasonable. I am fine with keeping this PR for now. I will keep looking into whether we should make the ordering guarantee explicit, how to fix FastGrouperImpl accordingly, and whether that would have a significant performance impact. If the performance impact turns out to be unacceptable, then we may need to reconsider whether order preservation should be promoted to an API contract. -- 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]
