Horton

Re: Option to not use ringbuffer in VACUUM, using it in failsafe mode

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org, Robert Haas <robertmhaas@gmail.com>, Melanie Plageman <melanieplageman@gmail.com>, David Rowley <dgrowleyml@gmail.com>
Date: 2023-01-11T18:35:19Z
Lists: pgsql-hackers 
On Wed, Jan 11, 2023 at 10:27 AM Andres Freund <andres@anarazel.de> wrote:
> Therefore I'd like to add an option to the VACUUM command to use to disable
> the use of the ringbuffer. Not sure about the name yet.

Sounds like a good idea.

> I think we should auto-enable that mode once we're using the failsafe mode,
> similar to [auto]vacuum cost delays getting disabled
> (c.f. lazy_check_wraparound_failsafe()). If things are bad enough that we're
> soon going to shut down, we want to be aggressive.

+1

-- 
Peter Geoghegan

Commits

  1. Add unit to vacuum_buffer_usage_limit value in postgresql.conf.sample.

  2. Improve VACUUM/ANALYZE BUFFER_USAGE_LIMIT docs

  3. Add --buffer-usage-limit option to vacuumdb

  4. Add VACUUM/ANALYZE BUFFER_USAGE_LIMIT option

  5. Move various prechecks from vacuum() into ExecVacuum()

  6. Always make a BufferAccessStrategy for ANALYZE

  7. Rename BufferAccessStrategyData.ring_size to nbuffers

  8. Disable vacuum's use of a buffer access strategy during failsafe

  9. Only make buffer strategy for vacuum when it's likely needed

  10. Remove some global variables from vacuum.c

  11. Doc: add Buffer Access Strategy to the glossary