Jie,
> What parameter I should change in order to make postmaster taking CPU
> as
> much as
> possible?
> Maybe I should ask: how can I make big tables equijoin faster?
> I have a serveral tables that contain more 2.5 million records, I
> need to
> equijoin
> those tables often.
There are several good articles on PostgreSQL performance tuning up at
http://techdocs.postgresql.org/
check 'em out.
-Josh