On Wed, Nov 7, 2012 at 1:42 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Lists <lists@benjamindsmith.com> writes:
>
>> ... because it
>> occasionally causes transactions and queries to hang when an update
>> causes a vacuum mid-day, effectively taking us offline randomly.
>
> I suspect this claim is based on ancient and no longer very relevant
> experience.
My experience is that if autovac is causing problems with stalled
queries etc you're either A: running ancient pg versions (pre 8.3), B:
Running WAY too aggressive settings in autovac (100 threads, no nap
time, cost limit of 100000 etc.) or C: Your IO subsystem is absolute
crap.
On any modern server, default autovac settings from 8.3 and on should
only have the possible problem of not being tuned aggressively enough.