Horton

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

Peter Geoghegan <pg@bowt.ie>

View thread View on postgr.es
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: 2023-01-11T19:20:51Z
Lists: pgsql-hackers 
On Wed, Jan 11, 2023 at 11:18 AM Andres Freund <andres@anarazel.de> wrote:
> I don't like that - it's also quite useful to disable use of ringbuffers when
> you actually need to clean up indexes. Especially when we have a lot of dead
> tuples we'll rescan indexes over and over...

That's a fair point.

My vote goes to "REUSE_BUFFERS", then.

-- 
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