Re: Potential ABI breakage in upcoming minor releases - Mailing list pgsql-hackers

On Fri, Nov 15, 2024 at 11:39:24PM +0530, Pavan Deolasee wrote:
> On Fri, Nov 15, 2024 at 11:22 PM Noah Misch <noah@leadboat.com> wrote:
> > > I'm starting to lean to the opinion that we need a re-wrap.
> >
> > Perhaps.  Even if we do rewrap for some reason, it's not a given that
> > restoring the old struct size is net beneficial.  If we restore the old
> > struct
> > size in v16.6, those who rebuild for v16.5 would need to rebuild again.
> > Hearing about other ResultRelInfo arrays will help clarify that decision.
>
> Looking more carefully at the usage of `ResultRelInfo` in the PGD code, I
> think we might also be impacted by it. At one place, we loop through the
> `es_result_relations` array and a size mismatch there will cause problems.
> Interestingly, in v14 and above, we read from `es_opened_result_relations`,
> which is a List, so it should be safe. I will try some tests on v13 to see
> if they result in crashes. But it seems quite likely by reading the code.

I agree.  I'm investigating the scope of damage from es_result_relations.