Re: pg15b2: large objects lost on upgrade

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: "Jonathan S. Katz" <jkatz@postgresql.org>

Cc: Peter Geoghegan <pg@bowt.ie>, Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, Noah Misch <noah@leadboat.com>, Andrew Dunstan <andrew@dunslane.net>, Bruce Momjian <bruce@momjian.us>, Michael Paquier <michael@paquier.xyz>, Justin Pryzby <pryzby@telsasoft.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Shruthi Gowda <gowdashru@gmail.com>

Date: 2022-08-03T23:19:41Z

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

"Jonathan S. Katz" <jkatz@postgresql.org> writes:
> I did rule out wanting to do the "xid + $X" check after reviewing some 
> of the output. I think that both $X could end up varying, and it really 
> feels like a bandaid.

It is that.  I wouldn't feel comfortable with $X less than 100 or so,
which is probably sloppy enough to draw Robert's ire.  Still, realizing
that what we want right now is a band-aid for 15beta3, I don't think
it's an unreasonable short-term option.

> Andres suggested upthread using "txid_current()" -- for the comparison, 
> that's one thing I looked at. Would any of the XID info from 
> "pg_control_checkpoint()" also serve for this test?

I like the idea of txid_current(), but we have no comparable
function for mxid do we?  While you could get both numbers from
pg_control_checkpoint(), I doubt that's sufficiently up-to-date.

			regards, tom lane