postmaster problem

Hi all,

According to a dbi mailing list buddy's instructions I set the env vars
like so in my /etc/profile

PGDATA=/usr/lib/pgsql
PGLIB=/usr/lib/pgsql
export PGDATA PGLIB

But still the problem exists...I can't connect to the pgsql monitor
program. I need to start the post master before I can successfully enter
the command
%> pgsql

running the postmaster gives me the following error:

[faqir(at)picard faqir]$ postmaster
/usr/bin/postmaster does not find the database system. Expected to find it
in t
he PGDATA directory "/usr/lib/pgsql", but unable to open file with pathname
"/us
r/lib/pgsql/base/template1/pg_class".

No data directory -- can't proceed.

All help is appreciated. Even it is just brainstorming type:)

With Thanks,

Sincerely,
Tahir

PS...by the way why is postmaster used or needed?