Re: BUG #18170: Unexpected error: no relation entry for relid 3

On 30/10/2023 09:24, Richard Guo wrote:
>
> On Sun, Oct 29, 2023 at 11:56 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us
> <mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us>> wrote:
>
> Alexander Korotkov <aekorotkov(at)gmail(dot)com
> <mailto:aekorotkov(at)gmail(dot)com>> writes:
> > I made some beautification of the patch by Andrei.  I also
> removed the
> > part which changes the target list for estimate_num_groups().  Any
> > objections to pushing this?
>
> It seems moderately likely that this will break as much as it fixes.
>
> I've not studied the original patch enough to understand why you need
> to be playing strange games with tree mutation rules, but I suspect
> that this is band-aiding over some rather fundamentally bad code.
>
>
> I also have some concerns about this patch.  It requires that
> root->parse remains unchanged during the whole subquery_planner() in
> order to work, which is an implicit constraint we did not have before.

It is not about unchanged; it is about referencing the same query at the
parent and child query blocks. Am I missing something?

--
regards,
Andrei Lepikhov
Postgres Professional