Re: Removing unneeded self joins

Hi!

On Mon, Feb 10, 2025 at 7:19 AM Andrei Lepikhov <lepihov(at)gmail(dot)com> wrote:
> On 9/2/2025 18:41, Alexander Korotkov wrote:
> > Regarding adjust_relid_set() and replace_relid(). I think they are
> > now strictly equivalent, except for the case then old relid is given
> > and not found. In this case adjust_relid_set() returns the original
> > relids while replace_relid() returns a copy. The behavior of
> > adjust_relid_set() appears more desirable as we don't need extra
> > copying when no modification is done. So, I've replaced all
> > replace_relid() with adjust_relid_set().
> Ok, I glanced into it, and it makes sense to merge these routines.
> I think the comment to adjust_relid_set() should be arranged, too. See
> the attachment for a short variant of such modification.
> >
> > Also, I did some grammar correction to your new comment in tests.
> Thanks!

I've further revised adjust_relid_set() header comment.

Looking back to the work done since previous attempt to commit this to
pg17, I can highlight following.
1) We're now using more of existing infrastructure including
adjust_relid_set() and ChangeVarNodes(). The most of complexity is
still there though.
2) We've checked few ways to further simplify this patch. But yet the
current way still feels to be best possible.
3) For sure, several bugs were fixed.

I think we could give it another chance for pg18 after some further
polishing (at least commit message still needs to be revised). Any
thoughts on this? Tom?

------
Regards,
Alexander Korotkov
Supabase