asolimando commented on PR #21828: URL: https://github.com/apache/datafusion/pull/21828#issuecomment-4351151810
> **On semantics** > > I agree with you and @asolimando that `OFFSET` without `ORDER BY` has no guaranteed ordering per SQL standard. This PR does **not** change the semantics — it produces exactly the same results as the current `GlobalLimitExec` skip (physical row order). The only difference is we skip rows at the parquet reader level (RG pruning + RowSelection) instead of reading and discarding them. Apologies if my comment read as referring to the PR, I only meant to address @AntoinePrv's comment, as I was afraid of the implications, although I definitely see where the ask is coming from, having worked closely to data scientists and data engineers in the past. This is very exciting work, and @alamb's proposal around using `ORDER BY row_number()` is an elegant way to optimize this even further for pagination. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
