Horton

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

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Melanie Plageman <melanieplageman@gmail.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Peter Geoghegan <pg@bowt.ie>, pgsql-hackers@postgresql.org, Robert Haas <robertmhaas@gmail.com>
Date: 2023-03-31T03:54:31Z
Lists: pgsql-hackers

Attachments

On Mon, 20 Mar 2023 at 11:50, Melanie Plageman
<melanieplageman@gmail.com> wrote:
> Attached is an updated v6.

I had a look over the v6-0001 patch.  There are a few things I think
could be done better:

"Some operations will access a large number of pages at a time", does
this really need "at a time"? I think it's more relevant that the
operation uses a large number of pages.

Missing <firstterm> around Buffer Access Strategy.

Various things could be linked to other sections of the glossary, e.g.
pages could link to glossary-data-page, shared buffers could link to
glossary-shared-memory and WAL could link to glossary-wal.

The final paragraph should have <command> tags around the various
commands that you list.

I have adjusted those and slightly reworded a few other things. See
the attached .diff which can be applied atop of v6-0001.

David

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