Alvaro Herrera wrote:
Karl Wright wrote:
This particular run lasted four days before a VACUUM became essential.
The symptom that indicates that VACUUM is needed seems to be that the
CPU usage of any given postgresql query skyrockets. Is this essentially
correct?
Are you saying you weren't used to run VACUUM all the time? If so,
that's where the problem lies.
Postgresql 7.4 VACUUM runs for so long that starting it with a cron job
even every 24 hours caused multiple instances of VACUUM to eventually be
running in my case. So I tried to find a VACUUM schedule that permitted
each individual vacuum to finish before the next one started. A vacuum
seemed to require 4-5 days with this particular database - or at least
it did for 7.4. So I had the VACUUM schedule set to run every six days.
I will be experimenting with 8.1 to see how long it takes to complete a
vacuum under load conditions tonight.
Karl
