In response to "Sorin N. Ciolofan" <ciolofan@ics.forth.gr>:
>
> Dear all,
>
> Thanks for your advices. I'd like to ask you where can I download the
> pg_buffercache add-on and also where can I find some documentation about how
> can I install it?
It's part of the contrib directory that ships with the source tarball.
Depending on your OS and associated packaging system (which you don't
bother to mention) it's probably available via RPMs or DEBs or whatever.
For example, under FreeBSD it's in /usr/ports/databases/postgresql-contrib
--
Bill Moran
http://www.potentialtech.com