Horton

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

Melanie Plageman <melanieplageman@gmail.com>

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From: Melanie Plageman <melanieplageman@gmail.com>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: David Rowley <dgrowleyml@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Andres Freund <andres@anarazel.de>, Justin Pryzby <pryzby@telsasoft.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Peter Geoghegan <pg@bowt.ie>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2023-04-26T12:59:13Z
Lists: pgsql-hackers 
On Wed, Apr 26, 2023 at 8:31 AM Daniel Gustafsson <daniel@yesql.se> wrote:

> > On 26 Apr 2023, at 13:26, David Rowley <dgrowleyml@gmail.com> wrote:
> > On Wed, 26 Apr 2023, 8:48 pm Masahiko Sawada, <sawada.mshk@gmail.com
> <mailto:sawada.mshk@gmail.com>> wrote:
>
> > It works but I think we might want to add the unit kB for
> > understandability and consistency with other GUC_UNIT_KB parameters.
> > I've attached a small patch that adds the unit and aligns the indent
> > of the comments to the perimeter parameters.
> >
> > I'm not currently able to check, but if work_mem has a unit in the
> sample conf then I agree that vacuum_buffer_usage_limit should too.
>
> +1 work_mem and all other related options in this section has a unit in the
> sample conf so adding this makes sense.
>

Agreed.
for the patch, the other GUCs have a tab instead of a space between the
unit and the "#" of the first comment.
(not the fault of this patch but probably makes sense to fix now).
Otherwise, LGTM

- Melanie

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