Horton

Re: improve performance of pg_dump with many sequences

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 Paquier <michael@paquier.xyz>, Euler Taveira <euler@eulerto.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2026-01-07T23:27:31Z
Lists: pgsql-hackers 
On Wed, Jan 07, 2026 at 06:13:48PM -0500, Tom Lane wrote:
> Nathan Bossart <nathandbossart@gmail.com> writes:
>> Before v18, pg_dump just ERRORs due to insufficient privileges on a
>> sequence.  IMHO that makes sense.  If you ask pg_dump to dump something you
>> don't have privileges on, I'd expect it to error instead of silently
>> skipping it.
> 
> That would be a fine argument were it not that collectSequences()
> tries to vacuum up the data for every sequence in the DB, whether
> the user has asked to dump them all or not.  In other places in
> pg_dump, we avoid such problems by restricting which tables we
> ask for data about ... but not here.

I meant that we could teach pg_dump to error in dumpSequenceData() if it
sees nulls for the sequence in question.

-- 
nathan

Commits

  1. pg_dump: Fix gathering of sequence information.

  2. Improve performance of dumpSequence().

  3. Improve performance of dumpSequenceData().

  4. Introduce pg_sequence_read_tuple().

  5. Parse sequence type and integer metadata in dumpSequence().