Re: Re: significant performance hit whenever autovacuum runs after upgrading from 9.0 -> 9.1

Lonni J Friedman <netllama(at)gmail(dot)com> writes:
> On Thu, May 24, 2012 at 12:34 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Can you correlate the performance hit with any specific part of
>> autovacuum? In particular, I'm wondering if it matters whether vacuum
>> is cleaning tables or indexes --- it alternates between the two, and the
>> access patterns are a bit different. You could probably watch what the
>> autovac process is doing with strace to see what it's accessing.

> Is there something specific I should be looking for in the strace
> output, or is this just a matter of correlating PID and FD to
> pg_class.relfilenode ?

Nah, just match up the files it touches with pg_class.relfilenode.

regards, tom lane