/var/run/postgresql ??

Hello, i have installed postgresql version 8.1.4-1.1 in Fedora 6

Since I'm very Linux unexperienced I used yum for this purpose.

I have all the commands installed, liek createdb (under /usr/bin/createdb
witch is not the location specified in the online manual), i also have the
psql "shell/interface" runing and i can manipulate the databases i create.
The postgresql deamon is up and running also.

The problem is this location "/var/run/postgresql" does not exists, i
searched in some foruns and it's mentioned a lot so i dont know why i dont
have it...

I'm using a postgres OCaml library witch has the parameter "
unix_domain_socket_dir = "/var/run/postgresql" " and when i try to compile
it i have the following error:

File "", line 0, characters 0-1:
Uncaught exception: Unix.Unix_error (20, "connect", "")
Uncaught exception: Unix.Unix_error(20, "connect", "")

I dont know if the problem comes from the above description (i think so, but
as i said i'm unexperienced in linux), but does any one know hot to fix it?
Did i miss something during install?? I installed the client, the server and
the libs were alredy installed...

Thank you
Manuel