Open Files

Hello all,

Recently I increased my maximum open files settings to 8192 on my
RedHat Linux 6.1 database server running postgres version 6.5.3

Since then I have been observeing /proc/sys/fs/file-nr and I noticed that the
system has already spiked to 8192 open files. I have also seen it sitting
steady at 7356 open files.

I was interested to know if this is "normal" behavior for Postgres, using
"lsof" I noticed
that most of the open files belonged to postmaster and most of them were
not sockets.

What do other people experience with "mid-size" db's?

Is there anywhere I can read about tuning shared memory, open files and
other paremeters
for a database server running postgres?

Any help is much apreciated.

Serge