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Re: pg_upgrade failing for 200+ million Large Objects

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Banck <mbanck@gmx.net>, Laurenz Albe <laurenz.albe@cybertec.at>, vignesh C <vignesh21@gmail.com>, "Kumar, Sachin" <ssetiya@amazon.com>, Robins Tharakan <tharakan@gmail.com>, Jan Wieck <jan@wi3ck.info>, Bruce Momjian <bruce@momjian.us>, Andrew Dunstan <andrew@dunslane.net>, Magnus Hagander <magnus@hagander.net>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2024-04-01T19:37:18Z
Lists: pgsql-hackers 
On Mon, Apr 01, 2024 at 03:28:26PM -0400, Tom Lane wrote:
> Nathan Bossart <nathandbossart@gmail.com> writes:
>> The one design point that worries me a little is the non-configurability of
>> --transaction-size in pg_upgrade.  I think it's fine to default it to 1,000
>> or something, but given how often I've had to fiddle with
>> max_locks_per_transaction, I'm wondering if we might regret hard-coding it.
> 
> Well, we could add a command-line switch to pg_upgrade, but I'm
> unconvinced that it'd be worth the trouble.  I think a very large
> fraction of users invoke pg_upgrade by means of packager-supplied
> scripts that are unlikely to provide a way to pass through such
> a switch.  I'm inclined to say let's leave it as-is until we get
> some actual field requests for a switch.

Okay.  I'll let you know if I see anything.  IIRC usually the pg_dump side
of pg_upgrade is more prone to lock exhaustion, so you may very well be
right that this is unnecessary.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Count individual SQL commands in pg_restore's --transaction-size mode.

  2. Reduce number of commands dumpTableSchema emits for binary upgrade.

  3. Invent --transaction-size option for pg_restore.

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

  5. Add temporal PRIMARY KEY and UNIQUE constraints

  6. Fix typo and case in messages