Re: [HACKERS] Autovacuum loose ends

"Michael Paesold" <mpaesold@gmx.at> writes:
> Alvaro Herrera wrote:
>> I still haven't added custom cost-based delays, but I don't see that as
>> a showstopper for removing it.  I just went through the CVS log and I
>> don't see anything else that applies.

> I think you should at least add an autovacuum specific value for
> "vacuum_cost_delay" because it turns cost-based vacuum delay on or off.

It occurs to me that you could have that today, using the knowledge that
the autovac daemon runs as the bootstrap user: use ALTER USER SET to
attach user-specific vacuum delay settings to that role.  This is a
pretty bletcherous solution, because (a) it requires knowledge of an
undocumented implementation detail and (b) it would interfere with using
that role for normal manual maintenance.  So I agree that a few extra
GUC settings would be better.  But we could get away without 'em.

Along the same lines, it was suggested that we need a way to disable
stats gathering on a per-database basis.  We already have it: you can
use ALTER DATABASE SET to control stats_row_level and stats_block_level
that way.  Neither of the above two objections apply to this usage, so
I think we can mark off that wishlist item as "done".  (Of course, the
soon-to-appear autovac documentation had better mention this trick.)

            regards, tom lane