Welcome to psql 8.2.4, the PostgreSQL interactive terminal.
Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit
I have been using PostgreSQL 8.2.4 since July. No problems so far. I use a custom kernel.
david@evenstar:~# cat /proc/sys/kernel/shmmax
david@evenstar:~# cat /proc/sys/kernel/shmall
My shmall value is exactly the one recommended by that page, but my shmmax is lower.
So far I haven't experienced any problems running PostgreSQL on a variety of PCs (most of them aren't dedicated database server and are running PostgreSQL along with X, KDE, Firefox, Eclipse and sometimes Mercury and Amarok). All those machines use my same custom kernel. None gave me any problems, excepting once when using a mutant version of OpenBravo.
I still prefer PostgreSQL over Oracle (it suits my needs).