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

On Fri, 7 Apr 2023 at 09:44, Melanie Plageman <melanieplageman@gmail.com> wrote:
> Otherwise, LGTM.

Thanks for looking.  I've also taken Justin's comments about the
README into account and fixed that part.

I've pushed the patch after a little more adjusting.  I added some
text to the docs that mention larger VACUUM_BUFFER_LIMITs can speed up
vacuum and also a reason why they might not want to go nuts with it.

I've also just now pushed the vacuumdb patch too. I ended up adjusting
some of the ERROR messages in the main patch after the following not
so nice user experience:

$ vacuumdb --buffer-usage-limit=1TB --analyze postgres
vacuumdb: vacuuming database "postgres"
SQL: VACUUM (SKIP_DATABASE_STATS, ANALYZE, BUFFER_USAGE_LIMIT '1TB')
vacuumdb: error: processing of database "postgres" failed: ERROR:
buffer_usage_limit option must be 0 or between 128 KB and 16777216 KB

$ vacuumdb --buffer-usage-limit=128KB --analyze postgres
vacuumdb: vacuuming database "postgres"
SQL: VACUUM (SKIP_DATABASE_STATS, ANALYZE, BUFFER_USAGE_LIMIT '128KB')
vacuumdb: error: processing of database "postgres" failed: ERROR:
value: "128KB": is invalid for buffer_usage_limit
HINT:  Valid units for this parameter are "B", "kB", "MB", "GB", and "TB".

David