Re: Horribly slow pg_upgrade performance with many Large Objects

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

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

To: Hannu Krosing <hannuk@google.com>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-04-07T21:25:32Z

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

Hannu Krosing <hannuk@google.com> writes:
> I have now met a not insignificant number of cases where pg_upgrade
> performance is really bad when the database has a large number of
> Large Objects.

What version are you testing?  We did some work in that area in the
v17 cycle (a45c78e32).

			regards, tom lane