Re: preserving db/ts/relfilenode OIDs across pg_upgrade (was Re: storing an explicit nonce)

On Sat, Jan 22, 2022 at 12:47:35PM +0530, Shruthi Gowda wrote:
> On Sat, Jan 22, 2022 at 12:27 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >
> > Robert Haas <robertmhaas@gmail.com> writes:
> > > It seems to me that what this comment is saying is that OIDs in the
> > > second and third categories are doled out by counters. Therefore, we
> > > can't know which of those OIDs will get used, or how many of them will
> > > get used, or which objects will get which OIDs. Therefore, I think we
> > > should go back to the approach that you were using for template0 and
> > > handle both that database and postgres using that method. That is,
> > > assign an OID manually, and make sure unused_oids knows that it should
> > > be counted as already used.
> >
> > Indeed.  If you're going to manually assign OIDs to these databases,
> > do it honestly, and put them into the range intended for that purpose.
> > Trying to take short-cuts is just going to cause trouble down the road.
> 
> Understood. I will rework the patch accordingly. Thanks

Thanks.  To get the rsync update reduction we need to preserve database
oids.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.