On Wed, Dec 3, 2008 at 2:00 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> It seems like mostly a confusion-generator to me. Is there any actual
> evidence that autovac should use a different maintenance_work_mem than
> other processes?
IMHO, the point is that we were used to consider the
maintenance_work_mem as a "one process at a time" thing. Even if it's
not really true, we usually didn't do maintenance task on a concurrent
basis.
The autovacuum workers change that and make it a default behaviour (as
we can have 3*maintenance_work_mem by default).
From my point of view, the best solution would be to share the
maintenance_work_mem amongst all the workers but I suppose it's not
technically possible.
--
Guillaume