Horton

Re: pg_upgrade: transfer pg_largeobject_metadata's files when possible

Nathan Bossart <nathandbossart@gmail.com>

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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: 2025-08-19T19:18:40Z
Lists: pgsql-hackers 
On Tue, Aug 19, 2025 at 09:49:26AM +0200, Hannu Krosing wrote:
> Have you considered re-creating pg_shdepend from
> pg_largeobject_metadata directly instead of having special cases for
> dumping it ?

I considered it when you last brought up the idea [0], but my testing
indicated that it's measurably slower.

> It would also be useful in cases of old (pg_upgraded since before pg
> 12) databases which might be missing it anyway.

We only use COPY for upgrades from v12 and newer, and the patch at hand
only applies to v16 and newer.  There should be no need to repair
pg_shdepend for any such upgrades because we haven't copied/linked the
files since before v12.

[0] https://postgr.es/m/CAMT0RQTXiqH7zdQEVSVd2L7_Cw4wQ1eHOD8hfZ%2B0vecMXJWc-w%40mail.gmail.com

-- 
nathan

Commits

  1. pg_upgrade: Use COPY for LO metadata for upgrades from < v12.

  2. pg_upgrade: Fix handling of pg_largeobject_metadata.

  3. pg_upgrade: Transfer pg_largeobject_metadata's files when possible.

  4. Rearrange pg_dump's handling of large objects for better efficiency.

  5. Expand AclMode to 64 bits

  6. Fix pg_upgrade for oid removal.