Nizar Ghazali <nghazali(at)yahoo(dot)com> writes:
> Im running postgres 7.4.3 on HP-UX 11.11. When I want
> to connect to my db, I have the following error:
> psql: FATAL: _mdfd_getrelnfd: cannot open relation
> pg_class: Permission denied
Sounds to me like you started the postmaster as the wrong user
(not the one who did initdb).
regards, tom lane