"Anne Rosset" <arosset(at)collab(dot)net> wrote:
> We are running some performances tests. With a lot of concurrent
> access, queries get very slow. When there is no load, those
> queries run fast.
What's "a lot"?
> We kind of see a trend about these queries: it seems like the
> ones that become very slow have an ORDER BY or MAX in them.
Without knowing the PostgreSQL version or more details about the
queries, I would only be guessing at the cause.
> It seems to me that we should try increasing shared_buffers. But
> do you have any other suggestions? Or do you see anything wrong in
> our config?
I don't think you showed us your whole PostgreSQL configuration, and
the format was hard to read -- it's best to show the contents of
your postgresql.conf file, minus comments.
If you read this page and re-post we can probably be more helpful:
http://wiki.postgresql.org/wiki/SlowQueryQuestions
-Kevin