Date: Thu, 15 Apr 2010 16:00:56 -0400
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Autovaccum with cost_delay does not complete on one
	solaris 5.10 machine
Message-ID: <20100415200056.GJ7259@alvh.no-ip.org>
References: <4BC76C9F.1020200@agliodbs.com>
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User-Agent: Mutt/1.5.20 (2009-06-14)

Josh Berkus wrote:

> Basically, vacuuming of a table which normally takes about 20 minutes
> interactively with vacuum_cost_delay set to 20 had not completed after
> 14 hours.  When I trussed it, I saw activity which indicated to me that
> autovacuum was doing a pollsys, presumably for cost_limit, every data page.
> 
> Autovacuum was running with vacuum_cost_limit = 200 and
> autovacuum_vacuum_cost_delay = 20, which I believe is the default for 8.3.
> 
> Truss output:
> 
> pollsys(0xFFFFFD7FFFDF83E0, 0, 0xFFFFFD7FFFDF8470, 0x00000000) = 0

So what is it polling?  Please try "truss -v pollsys"; is there a way in
Solaris to report what each file descriptor is pointing to?  (In linux
I'd look at /proc/<pid>/fd)

We don't call pollsys anywhere.  Something in Solaris must be doing it
under the hood.

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