ninglinLiu opened a new pull request, #26918: URL: https://github.com/apache/datafusion/pull/26918
## Which issue does this PR close? Closes #26910. ## Rationale for this change The preimage rewrite turns `floor(x) = 3` into `x >= 3 AND x < 4`. When `x` is volatile (e.g. `random() * 10`), each copy draws a new value, so `floor(random() * 10) = 3` returns ~28% of rows instead of ~10%. `get_preimage` already requires an immutable UDF; this also skips the rewrite when any argument expression is volatile. ## What changes are included in this PR? - Guard in `get_preimage` with `args.iter().any(Expr::is_volatile)` - sqllogictest EXPLAIN cases in `floor_preimage.slt` showing the rewrite is skipped for `floor(random() * 10)` ## Are these changes tested? Yes — new sqllogictest cases in `floor_preimage.slt`. ## Are there any user-facing changes? No (correctness fix for an optimizer rewrite). ## AI assistance AI-assisted (Cursor). I verified the volatile-argument path in `get_preimage`, confirmed the EXPLAIN plans, and wrote the commit message. -- 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]
