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

On Wed, May 23, 2012 at 3:33 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Gavin Flower <GavinFlower(at)archidevsys(dot)co(dot)nz> writes:
>>> 16 core Xeon X5550 2.67GHz
>>> 128GB RAM
>>> $PGDATA sits on a RAID5 array comprised of 3 SATA disks.  Its Linux's
>>> md software RAID.
>
>> How does this compare to your other machines running the same, or
>> similar, databases?
>> However, you do say that the other machines are indentical - but are the
>> other
>> machines different in any aspect, that might prove siginificant?
>
> I think Lonnie said that the other machines are just running standby
> clusters, which would mean they aren't running autovacuum as such,
> merely applying any WAL it produces.  So that could be plenty enough
> to explain a difference in kernel-visible behavior.

Yes, that is correct.