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: 2024-07-17T19:05:03Z
Lists: pgsql-hackers 
On Wed, Jul 17, 2024 at 02:59:26PM -0400, Tom Lane wrote:
> Nathan Bossart <nathandbossart@gmail.com> writes:
>> On second thought, I worry that this change might needlessly complicate the
>> pg_sequences system view.  Maybe we should just add a
>> pg_sequence_get_tuple() function that returns everything in
>> FormData_pg_sequence_data for a given sequence OID...
> 
> Uh ... why do we need a function, rather than just
> 
> select * from pg_sequence

We can use that for dumpSequence(), but dumpSequenceData() requires
information from the sequence tuple itself.  Right now, we query each
sequence relation individually for that data, and I'm trying to find a way
to cut down on those round trips.

-- 
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().