On Fri, 2 May 2008, Alexy Khrabrov wrote:
> I have an UPDATE query updating a 100 million row table, and
> allocate enough memory via shared_buffers=1500MB.
In addition to reducing that as you've been advised, you'll probably need
to increase checkpoint_segments significantly from the default (3) in
order to get good performance on an update that large. Something like 30
would be a reasonable starting point.
I'd suggest doing those two things, seeing how things go, and reporting
back if you still think performance is unacceptable. We'd need to know
your PostgreSQL version in order to really target future suggestions.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD