Re: [PATCH] Fix null pointer dereference in PG19

On Tue, Apr 21, 2026 at 8:24 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Aleksander Alekseev <aleksander(at)tigerdata(dot)com> writes:
> > I propose fixing this by explicitly forbidding using the named
> > features together. See the patch.
>
> Checking this at parse time is completely the wrong thing.
> The view could have gained (or lost) triggers by the time
> it's executed.
>
> Actually, looking at it, transformForPortionOfClause is quite
> full of premature error checks:
>
> * I'd tend to move the anti-FDW check to execution too.
> It's not actively wrong, since nowadays we don't permit
> relations to change relkind, but it seems out of place.
> Also, it seems inadequate to deal with the case of a target
> that is a partitioned table having FDW partitions.
>
> * contain_volatile_functions_after_planning is utterly wrong
> to apply here. That should happen somewhere in the planner,
> where it'd be cheaper as well as not premature.
>
> * I'm inclined to think that pretty much all the mucking with
> opclasses is misplaced too: those structures are not immutable
> either. All of that should move to rewriting, planning, or
> even executor startup.

Thanks for this feedback! I will work on a patch to move those checks
to different phases, and also guard against FDW partitions.

Yours,

--
Paul ~{:-)
pj(at)illuminatedcomputing(dot)com