From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
---|---|
To: | Larry Rosenman <ler(at)lerctr(dot)org> |
Cc: | Jim Nasby <jnasby(at)pervasive(dot)com>, "'Tom Lane'" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "'Jim C(dot) Nasby'" <jim(at)nasby(dot)net>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Autovacuum on by default? |
Date: | 2006-08-24 13:38:43 |
Message-ID: | 20060824133843.GB18349@alvh.no-ip.org |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Larry Rosenman wrote:
> Jim C. Nasby wrote:
> > On Tue, Aug 22, 2006 at 11:08:49AM -0400, Tom Lane wrote:
> >> "Jim C. Nasby" <jim(at)nasby(dot)net> writes:
> >>> If there's a bunch of activity on a table but stats are reset
> >>> before a vacuum is run on it and then a vacuum is run, the user
> >>> will still be left thinking that the table needs to be vacuumed.
> >>
> >> Except that autovac *won't* vacuum it if the stats have been reset.
> >> So I'm not seeing that there's really a problem in practice.
> >
> > IIRC the stats also include info about regular (manual) vacuums, so
> > the above scenario still applies.
>
> They do. The stats patch as applied captures both autovacuum and manual
> vacuum
> as well as analyze (both from the Autovacuum daemon and manual).
But the original point still remains: if you manually VACUUM a table
that does not have a pgstat entry, the pgstat system will drop the
"vacuum timestamp" message on the floor without recreating the entry.
I think there is a reasonable case for saying that a manual vacuum could
hint pgstat to create the entry instead. On the other hand, if
autovacuum never vacuums a table with no pgstat entry, then you could
just create the pgstat entry in both cases and it would be the same
anyway.
--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.
From | Date | Subject | |
---|---|---|---|
Next Message | Alvaro Herrera | 2006-08-24 13:45:23 | Re: invalid byte sequence ? |
Previous Message | Larry Rosenman | 2006-08-24 13:35:03 | Re: Autovacuum on by default? |