Re: Teaching planner to short-circuit empty UNION/EXCEPT/INTERSECT inputs

On Tue, 4 Nov 2025 at 22:54, David Rowley <dgrowleyml@gmail.com> wrote:
> The reason we end up with the same result_rel is that we're not
> passing all the relids in fetch_upper_rel(root, UPPERREL_SETOP,
> relids) due to having removed dummy rels. I guess the fix might be
> something like record the relids even when skipping dummy relations.
> I'll go and explore that as an option.

This seems to fix it. I'll study it more in the morning (it's late in
my time zone).

David