Horton

Re: pg15b2: large objects lost on upgrade

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-hackers@postgresql.org, Bruce Momjian <bruce@momjian.us>, Shruthi Gowda <gowdashru@gmail.com>
Date: 2022-07-06T11:56:00Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Revert recent changes to 002_pg_upgrade.pl.

  2. Revise test case added in 43746996399541ecb5c7b188725a5f097c15ceae.

  3. Use TRUNCATE to preserve relfilenode for pg_largeobject + index.

  4. Preserve relfilenode of pg_largeobject and its index across pg_upgrade.

  5. Have VACUUM warn on relfrozenxid "in the future".

  6. Set relfrozenxid to oldest extant XID seen by VACUUM.

  7. pg_upgrade: Preserve relfilenodes and tablespace OIDs.

  8. Perform a lot more sanity checks when freezing tuples.

On Tue, Jul 05, 2022 at 02:40:21PM -0400, Robert Haas wrote:
> On Tue, Jul 5, 2022 at 12:56 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> > My patch also leaves a 0 byte file around from initdb, which is harmless, but
> > dirty.
> >
> > I've seen before where a bunch of 0 byte files are abandoned in an
> > otherwise-empty tablespace, with no associated relation, and I have to "rm"
> > them to be able to drop the tablespace.  Maybe that's a known issue, maybe it's
> > due to crashes or other edge case, maybe it's of no consequence, and maybe it's
> > already been fixed or being fixed already.  But it'd be nice to avoid another
> > way to have a 0 byte files - especially ones named with system OIDs.
> 
> Do you want to add something to the patch to have pg_upgrade remove
> the stray file?

I'm looking into it, but it'd help to hear suggestions about where to put it.
My current ideas aren't very good.

-- 
Justin