Date: Thu, 8 Mar 2007 14:53:30 -0300
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: pgsql-patches@postgresql.org
Subject: Re: log_autovacuum
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Simon Riggs wrote:
> log_autovacuum = on produces a single line of output from autovacuum,
> with additional useful stats. Patch is proving useful in performance
> testing. Not sure what is intended on logging for 8.3....
> 
> LOG:  autovac "public.w" scans:1 pages:197(-0) tuples:2338(-7199) CPU
> 0.00s/0.00u sec elapsed 0.39 sec
> LOG:  autovac "public.s" scans:1 pages:1926746(-0)
> tuples:37000611(-3461867) CPU 99.74s/53.37u sec elapsed 7977.20 sec

I agree something like this is useful, but I'd try to get rid of cryptic
notation, and maybe split in several message categories if reasonable.

Your proposal is

LOG:  autovac "public.w" scans:1 pages:197(-0) tuples:2338(-7199) CPU 0.00s/0.00u sec elapsed 0.39 sec

This looks too much like the old VACUUM VERBOSE reporting, which was
awful.  Maybe something like this is better:

LOG: index passes: 1  pages: removed 0, 197 remain  tuples: removed 7199, 2338 remain  CPU usage: whatever
CONTEXT: Automatic vacuuming of table "database.public.w"

This looks like the sort of thing comparable to picking a bikeshed color
though :-(

Keep in mind that it's going to be translated, so it's not useful for
machine parsing anyway.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support