Re: Pro et contra of preserving pg_proc oids during pg_upgrade

On Thu, Oct 12, 2023 at 7:36 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Nikita Malakhov <hukutoc(at)gmail(dot)com> writes:
> > Please advise on the idea of preserving pg_proc oids during pg_upgrade,
> in
> > a way like relfilenodes, type id and so on. What are possible downsides
> of
> > such a solution?
>
> You have the burden of proof backwards. That would add a great deal
> of new mechanism, and you haven't provided even one reason why it'd
> be worth doing.
>
>
I was curious about the comment regarding type oids being copied over and I
found the commentary in pg_upgrade.c that describes which oids are copied
over and why, but the IMPLEMENTATION seems to be out-of-sync with the
actual implementation.

"""
It preserves the relfilenode numbers so TOAST and other references
to relfilenodes in user data is preserved. (See binary-upgrade usage
in pg_dump). We choose to preserve tablespace and database OIDs as well.
"""

David J.