Re: Horribly slow pg_upgrade performance with many Large Objects

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Hannu Krosing <hannuk@google.com>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Nitin Motiani <nitinmotiani@google.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-07-21T14:38:57Z

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 →

pg_upgrade: Use COPY for large object metadata.
- 161a3e8b682e 19 (unreleased) landed
pg_dump: Fix object-type sort priority for large objects.
- fb6c860bbd1f 19 (unreleased) landed
- e43fae199e50 17.6 landed
- 36026b0fe3ab 18.0 landed
pg_upgrade: Mention that we preserve database OIDs in a comment.
- e2665efd0f4d 18.0 landed
pg_upgrade: Preserve database OIDs.
- aa01051418f1 15.0 cited
Fix pg_upgrade for oid removal.
- 12a53c732ced 12.0 cited

On Mon, Jul 21, 2025 at 02:03:45AM +0200, Hannu Krosing wrote:
> Do you think the current patch could be backported to at least some
> latest versions ?

I think that's pretty unlikely.  It'd be a pretty big departure from our
versioning policy.  In the past, we have back-patched "critical"
performance fixes, but that involved changes that had already been in
released versions for years.

-- 
nathan