Re: Autovaccum with cost_delay does not complete on one solaris 5.10 machine

From: Alvaro Herrera
Subject: Re: Autovaccum with cost_delay does not complete on one solaris 5.10 machine
Date: ,
Msg-id: 20100415202405.GL7259@alvh.no-ip.org
(view: Whole thread, Raw)
In response to: Re: Autovaccum with cost_delay does not complete on one solaris 5.10 machine  (Tom Lane)
Responses: Re: Autovaccum with cost_delay does not complete on one solaris 5.10 machine  (Josh Berkus)
List: pgsql-performance


Tom Lane wrote:
> Alvaro Herrera <> writes:
> > We don't call pollsys anywhere.  Something in Solaris must be doing it
> > under the hood.
>
> pg_usleep calls select(), and some googling indicates that select() is
> implemented as pollsys() on recent Solaris versions.  So Josh's
> assumption that those are delay calls seems plausible.  But it shouldn't
> be sleeping after each page with normal cost_delay parameters, should it?

Certainly not ... The only explanation would be that the cost balance
gets over the limit very frequently.  So one of the params would have to
be abnormally high (vacuum_cost_page_hit, vacuum_cost_page_miss,
vacuum_cost_page_dirty).

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.


pgsql-performance by date:

From: Dave Crooke
Date:
Subject: SOLVED: Re: HELP: How to tame the 8.3.x JDBC driver with a biq guery result set
From: Віталій Тимчишин
Date:
Subject: Planner not using column limit specified for one column for another column equal to first