From: Michael Crozier <crozierm@conducivetech.com>
To: pgsql-performance@postgresql.org
Subject: Re: Autovacuum / full vacuum (off-topic?)
Date: Wed, 18 Jan 2006 11:15:51 -0800
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On Wednesday 18 January 2006 08:54 am, Chris Browne wrote:
> To the contrary, there is a whole section on what functionality to
> *ADD* to VACUUM.

Near but not quite off the topic of VACUUM and new features...

I've been thinking about parsing the vacuum output and storing it in 
Postgresql.  All the tuple, page, cpu time, etc... information would be 
inserted into a reasonably flat set of tables.

The benefits I would expect from this are:

* monitoring ability - I could routinely monitor the values in the table to 
warn when vacuum's are failing or reclaimed space has risen dramatically.  I 
find it easier to write and maintain monitoring agents that perform SQL 
queries than ones that need to routinely parse log files and coordinate with 
cron.

* historical perspective on tuple use - which a relatively small amount of 
storage, I could use the vacuum output to get an idea of usage levels over 
time, which is beneficial for planning additional capacity

* historical information could theoretically inform the autovacuum, though I 
assume there are better alternatives planned.

* it could cut down on traffic on this list if admin could see routine 
maintenance in a historical context.

Assuming this isn't a fundamentally horrible idea, it would be nice if there 
were ways to do this without parsing the pretty-printed vacuum text (ie, 
callbacks, triggers, guc variable).

I'd like to know if anybody does this already, thinks its a bad idea, or can 
knock me on the noggin with the pg manual and say, "it's already there!".

Regards,

 Michael