Re: Huge performance problem between 7.4.1 and 8.0.3 - CS issue?

Robert Creager <Robert_Creager@StorageTek.com> writes:
> Alright.  Restarted the 803 database.  Cron based vacuum analyze is
> running every 5 minutes.  vacuum_cost_delay is 0.  The problem showed
> up after about 1/2 hour of running.  I've got vacuum jobs stacked from
> the last 35 minutes, with 2 vacuums running at the same time.  CS is
> around 73k.

Hmm, I hadn't thought about the possible impact of multiple concurrent
vacuums.  Is the problem caused by that, or has performance already gone
into the tank by the time the cron-driven vacuums are taking long enough
to overlap?

            regards, tom lane