Re: pg_clog questions

Alvaro Herrera wrote:
> Tom Lane wrote:
>> Hm.  I believe that autovac only does database-wide vacuums when it
>> thinks they're necessary to prevent transaction wraparound failures.
>> Which would mean that it'd let pg_clog grow to something on the order
>> of half a gig before any truncation would happen.  That's probably
>> insufficiently aggressive :-(
>>
>> Alvaro, Matthew, any thoughts about improving that?

Not really.  Alvara mentioned reducing the constant that we test against
for DB wide vacuum.  I'm a little concerned that might result is
database-wide vacuums more often than desired, but I don't see a better
answer off the top of my head.