Re: remove_useless_joins vs. bug #19560 - Mailing list pgsql-hackers

On Fri, Sep 25, 2026 at 8:43 PM Ayush Tiwari
<ayushtiwari.slg01@gmail.com> wrote:
> Would it make sense to skip PHVs during that argument walk too,
> while still processing other SubLinks in the argument? The attached
> patch tries that, with small tests for sum() and GROUPING().

Skipping PHVs in build_subplan looks right to me.  Any PHV found
within the arguments of an outer-level Aggref is a pushed-down copy
that its owning level has already preprocessed, so there is nothing
left to do in it.  The flag looks ugly though, but I don't have a
better fix than that.

I plan to push this fix soon if there are no objections.

- Richard