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

On Thu, Aug 26, 2021 at 11:35:01AM -0400, Robert Haas wrote:
> On Thu, Aug 26, 2021 at 11:24 AM Bruce Momjian <bruce@momjian.us> wrote:
> > On Thu, Aug 26, 2021 at 11:00:47AM -0400, Robert Haas wrote:
> > > Anyone see a flaw in that analysis?
> >
> > I am still waiting to hear the purpose of this preservation.  As long as
> > you don't apply the patch, I guess I will just stop asking.
> 
> You make it sound like I didn't answer that question the last time you
> asked it, but I did.[1] I went back to the previous thread and found
> that, in fact, there's at least one email *from you* appearing to
> endorse that concept for reasons unrelated to TDE[2] and another where
> you appear to agree that it would be useful for TDE to do it.[3]
> Stephen Frost also wrote up his discussion during the Unconference and
> some of his reasons for liking the idea.[4]
> 
> If you've changed your mind about this being a good idea, or if you no
> longer think it's useful without TDE, that's fine. Everyone is
> entitled to change their opinion. But then please say that straight
> out. It baffles me why you're now acting as if it hasn't been
> discussed when it clearly has been, and both you and I were
> participants in that discussion.
> 
> [1] https://www.postgresql.org/message-id/CA+Tgmob7msyh3VRaY87USr22UakvvSyy4zBaQw2AO2CfoUD3rA@mail.gmail.com
> [2] https://www.postgresql.org/message-id/20210601140949.GC22012@momjian.us
> [3] https://www.postgresql.org/message-id/20210527210023.GJ5646@momjian.us
> [4] https://www.postgresql.org/message-id/20210531201652.GY20766@tamriel.snowman.net

Yes, it would help incremental backup of pgBackRest, as reported by the
developers.  However, I have seen no discussion if this is useful enough
reason to add the complexity to preserve this.  The TODO list shows
"Desirability" as the first item to be discussed, so I expected that to
be discussed first.  Also, with TDE not progressing (and my approach not
even needing this), I have not seen a full discussion if this item is
desirable based on its complexity.

What I did see is this patch appear with no context of why it is useful
given our current plans, except for pgBackRest, which I think I
mentioned.

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

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