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: Andres Freund <andres@anarazel.de>
Cc: Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>, Nitin Motiani <nitinmotiani@google.com>, Hannu Krosing <hannuk@google.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-02-05T21:29:55Z
Lists: pgsql-hackers

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On Thu, Feb 05, 2026 at 02:30:28PM -0600, Nathan Bossart wrote:
> On Thu, Feb 05, 2026 at 03:23:38PM -0500, Andres Freund wrote:
>> On 2026-02-05 13:31:23 -0600, Nathan Bossart wrote:
>>> In theory, we could update the pg_largeobject_metadata query to only
>>> retrieve LOs with comments and security labels.  I'm not sure it's worth
>>> trying to optimize further than that; we've long operated under the
>>> assumption that comments/seclabels on LOs are pretty rare.
>> 
>> I think that'd be a huge improvement. Right now it's not hard to get into a
>> situation where you have too many LOs to not have enough memory to do a
>> pg_upgrade.
> 
> It seems to work.  I'm working on a nicer patch for all this stuff.

Here is what I have so far.

-- 
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.