On Tue, Aug 24, 2021 at 02:34:26PM -0400, Robert Haas wrote:
> On Tue, Aug 24, 2021 at 2:16 PM Bruce Momjian <bruce@momjian.us> wrote:
> > One other issue --- the more that pg_upgrade preserves, the more likely
> > pg_upgrade will break when some internal changes happen in Postgres.
> > Therefore, if you want pg_upgrade to preserve something, you have to
> > have a good reason --- even code simplicity might not be a sufficient
> > reason.
>
> While I accept that as a general principle, I don't think it's really
> applicable in this case. pg_upgrade already knows all about
> relfilenodes; it has a source file called relfilenode.c. I don't see
> that a pg_upgrade that preserves relfilenodes is any more or less
> likely to break in the future than a pg_upgrade that renumbers all the
> files so that the relation OID and the relfilenode are equal. You've
> got about the same amount of reliance on the on-disk layout either
> way.
I was making more of a general statement that preservation can be
problematic and its impact must be researched.
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com
If only the physical world exists, free will is an illusion.
