On Thu, May 8, 2025 at 5:41 AM Bruce Momjian <bruce@momjian.us> wrote:
> On Wed, May 7, 2025 at 03:03:32PM +0900, Richard Guo wrote:
> > I'm wondering if we should consider mentioning that several
> > long-standing issues related to grouping sets have been fixed starting
> > from PostgreSQL v18. I understand that we typically don't include bug
> > fixes in the release notes, but these particular issues have been
> > present since grouping sets were first introduced, and currently they
> > still exist in the back branches (yeah, for some reason we do not have
> > back-branch fixes; we only fix them in v18 and going forward).
> >
> > There have been complaints from users about grouping sets giving
> > incorrect results in certain cases, which has made them hesitant to
> > use PostgreSQL for analytical workloads. Since these issues are fixed
> > in v18, it might be worthwhile to point this out — if only to reassure
> > users that these issues are no longer a concern going forward.
> >
> > (FWIW, the related commits are 247dea89f, f5050f795, and cc5d98525).
>
> Agreed, any fix that commonly used to return wrong results should be
> mentioned. Applied patch attached.
I'm not sure whether it's appropriate to put the incorrect-result
fixes under the item "Allow some HAVING clauses on GROUPING SETS to
be pushed to WHERE clauses", since that item is an optimization and
does not fix these incorrect-result issues.
But I'm also unsure where else they should go. Would it make sense to
list them as a new item instead?
Thanks
Richard
