Horton

Re: improve performance of pg_dump with many sequences

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Euler Taveira <euler@eulerto.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2026-01-07T23:13:48Z
Lists: pgsql-hackers 
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.

			regards, tom lane

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().