Re: Reducing the WAL overhead of freezing in VACUUM by deduplicating per-tuple freeze plans

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-09-22T04:22:48Z
Lists: pgsql-hackers
On Wed, Sep 21, 2022 at 02:11:36PM -0700, Peter Geoghegan wrote:
> On Wed, Sep 21, 2022 at 1:14 PM Nathan Bossart <nathandbossart@gmail.com> wrote:
>> Presumably a
>> generic WAL record compression mechanism could be reused for other large
>> records, too.  That could be much easier than devising a deduplication
>> strategy for every record type.
> 
> It's quite possible that that's a good idea, but that should probably
> work as an additive thing. That's something that I think of as a
> "clever technique", whereas I'm focussed on just not being naive in
> how we represent this one specific WAL record type.

Got it.  I think that's a fair point.

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



Commits

  1. Rename and relocate freeze plan dedup routines.

  2. Deduplicate freeze plans in freeze WAL records.