Re: pg15b2: large objects lost on upgrade

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Justin Pryzby <pryzby@telsasoft.com>

Cc: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Bruce Momjian <bruce@momjian.us>, Shruthi Gowda <gowdashru@gmail.com>

Date: 2022-07-07T17:38:44Z

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 →

Revert recent changes to 002_pg_upgrade.pl.
- 6f7e7d0c482d 15.0 landed
- 87e22f675fd8 16.0 landed
Revise test case added in 43746996399541ecb5c7b188725a5f097c15ceae.
- d92f2bc0dae3 15.0 landed
- 212bdc0cbc32 16.0 landed
Use TRUNCATE to preserve relfilenode for pg_largeobject + index.
- bbe08b8869bd 16.0 landed
- 4ab5dae9472c 15.0 landed
Preserve relfilenode of pg_largeobject and its index across pg_upgrade.
- a2996478c32d 15.0 landed
- d498e052b4b8 16.0 landed
Have VACUUM warn on relfrozenxid "in the future".
- e83ebfe6d767 15.0 cited
Set relfrozenxid to oldest extant XID seen by VACUUM.
- 0b018fabaaba 15.0 cited
pg_upgrade: Preserve relfilenodes and tablespace OIDs.
- 9a974cbcba00 15.0 cited
Perform a lot more sanity checks when freezing tuples.
- 699bf7d05c68 11.0 cited

On Thu, Jul 7, 2022 at 1:10 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> Maybe it's a good idea to check that the file is empty before unlinking...

If we want to verify that there are no large objects in the cluster,
we could do that in check_new_cluster_is_empty(). However, even if
there aren't, the length of the file could still be more than 0, if
there were some large objects previously and then they were removed.
So it's not entirely obvious to me that we should refuse to remove a
non-empty file.

-- 
Robert Haas
EDB: http://www.enterprisedb.com