On 8/30/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "Marko Kreen" <markokr@gmail.com> writes:
> > Note that it's much better to err on the smaller values.
>
> > Extra index pass is really no problem.
>
> I beg to differ ...
Well, if Postgres tries to cut down passes by using max memory
then admin is forced to cut down maint_mem for safety reasons...
> What this may actually suggest is that autovacuum needs its own value of
> "maintenance_work_mem", or that it should automatically divide the value
> by the authorized number of workers.
+1
Autovacuum having it's own value and cutting pieces from there
and giving to vacuums is probably the easiest path.
Then the per-backend maint_mem does not need to be large.
--
marko