Where is locking done?

Here's my dillema:

We are currently building a site with multiple machines to run our website 
and client sites as well.  I would like to run the postgres binary on 2 
machines concurrently to assist in load balancing.  $PGDATA will be kept on 
a RAID 1+0.    I need to know where postgres does it's row & table locking. If it's done in memory, I've got some
problems! If it's done at or near 
 
the $PGDATA directory (which sounds like bad performance decision) that 
would be piece of cake.    Any advice or ideas on this issue would be 
GREATLY appreciated.

Thanks in advance!!

Larry


-- 
Lawrence M. Kagan
Allied Infosystems, Inc.
E-mail:    larry@alliedinfosystems.com
Web:       www.alliedinfo.com
Phone:     (954) 647-4600
Toll-free: (877) WEB-5888