Re: PG 18 release notes draft committed

On Fri, May 9, 2025 at 12:05:07PM +0900, Richard Guo wrote:
> > I think there are two patterns here:
> >
> > * 247dea89f and cc5d98525 fix cases where grouping expressions fail to
> > match lower-level target items due to expression preprocessing or
> > subquery pull-up. Subqueries are one example of such expressions.
> >
> > * f5050f795 fixes cases where some seemingly redundant grouping or
> > ordering expressions were incorrectly ignored, without recognizing
> > that they could be nulled by grouping sets.
> >
> > I don't think this constitutes an incompatibility, and it's unlikely
> > that anyone is relying on the old behavior, as it was clearly
> > incorrect.
> >
> > (I realize these descriptions are too technical, but I'm not sure how
> > to express them in a more user-facing way.)
>
> How about putting them this way:
>
> * 247dea89f and cc5d98525 fix queries in which GROUP BY columns
> contain expressions that are complex or originate from subqueries.
>
> * f5050f795 fixes queries in which ORDER BY columns contain
> expressions that are used in grouping sets.

Okay, that is clear. Let's stay with what we have in the release notes
and see if we get any feedback from users during the beta period; that
might give us direction on whether we want to expand what we already
have. Thanks.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Do not let urgent matters crowd out time for investment in the future.