Re: Performance degrade running on multicore computer

afancy <groupme@gmail.com> writes:
> My PostgreSQL server has two CPUs (OS: Fedora 11), each with 4 cores. Total
> is 8cores.  Now I have several clients running at the same time to do insert
> and update on the same table, each client having its own connection.  I have
> made  two testing with  clients running in parallel to load 20M data in
> total. Each testing, the data is split evenly by the client number such that
> each client only loads a piece of data.

What exactly are you doing when you "load data"?  There are some code
paths that are slower if they have to examine not-yet-committed tuples,
and your report sounds a bit like that might be what's happening.
But with so few details (not even a Postgres version number :-()
it's difficult to be sure of anything.

            regards, tom lane