Peter Wilson <petew@yellowhawk.co.uk> writes:
> I'd tweaked a couple of parameters in postgres.conf - the significant one I
> thought being random_page_cost, so I changed this back to default and did a
> 'service postgresql reload' - no difference, but I wasn't sure whether this
> could be changed via reload so I restarted Postgres.
> The restart fixed the problem. The 85 second insert time dropped back down to 5
> seconds!!!
Um, which parameters did you change *exactly*?
Also, depending on how you were submitting the queries, it's possible
that Postgres was using cached plans already made based on the old
settings. In that case the restart would've cleared the bad plans
(but starting a fresh connection would've been sufficient for that).
regards, tom lane