Aggressive autovacuuming ?

Hi.

I have been wondering if anyone has been experimenting with "really
agressive"
autovacuuming. The database I'm adminstrating rarely have "long running"
transactions
(over several minutes). And a fair amount of buffercache and an OS cache of
(at best 64GB). A lot of the OS cache is being used for read-caching.

My thought was that if I tuned autovacuum to be "really aggressive" then
I could get autovacuum to actually vacuum the tuples before they
get evicted from the OS cache thus effectively "saving" the IO-overhead
of vacuuming.

The largest consequence I can see at the moment is that when I get a
full vacuum (for preventing transaction-id wraparound) it would be
run with the same aggressive settings, thus giving a real performance
hit in that situation.

Has anyone tried to do similar? What is your experience?
Is the idea totally bogus?

Jesper

--
Jesper Krogh