Re: Autovacuum / full vacuum (off-topic?)

On Wed, Jan 18, 2006 at 03:36:04PM -0800, Michael Crozier wrote:
>
> On Wednesday 18 January 2006 14:52 pm, Jim C. Nasby wrote:
> > I think it's a good idea, but you should take a look at the recently
> > added functionality that allows you to investigate the contests of the
> > FSM via a user function (this is either in 8.1 or in HEAD; I can't
> > remember which).
>
> I will look at this when time allows. Perhaps there is a combination of
> triggers on stat tables and asynchronous notifications that would provide
> this functionality without getting too deep into the vacuum's transaction
> logic?

You can't put triggers on system tables, at least not ones that will be
triggered by system operations themselves, because the backend bypasses
normal access methods. Also, most of the really interesting info isn't
logged anywhere in a system table; stuff like the amount of dead space,
tuples removed, etc.

> Were it too integrated with the vacuum, it would likely be too much for
> contrib/, I assume.

Probably.

A good alternative might be allowing vacuum to output some
machine-friendly information (maybe into a backend-writable file?) and
then have code that could load that into a table (though presumably that
could should be as simple as just a COPY).
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461