Due to large number of Sale orders, the size of pg_toast, public.mail_message, pubic.mail_message_message_id.index tables is increasing exponentially.  Sale Order & Sale Order line table size is around 200 MB while above mentioned tables has crossed 700 MB and soon will touch GB. It has really degraded the performance, timer icon is just moving on and on for pretty long time (>10 min or more). We really do not need messaging, so will disabling messaging help?  System resources are pretty nice 6GB and 3 Cores and connected users are less than 10.

What is the best way to configure openerp/postgre so db size can be controlled and performance can be improved.