restoring from dump

Hi Everybody,

I had a machine crash a couple of days ago, from which
I have recovered (ie., postgres is running now), but I
want to restore from a dump I had made.  The dump is
made by pg_dumpall and I have a gzipped file.

I am a bit unclear as to how to proceed.

(A) I get rid of what I have now and use createdb to
    make a "new" database and use psql.

(B) Don't bother with createdb and let the tables be
    overwritten.

Also the manual tells me (in section 24.1.2):
  psql -f infile postgres
The last parameter: "postgres" is this the database
super-user?  If so, do I need to spell it out if I am
logged in as user postgres?  If not, what is this?

Please advise.  I would appreciate it.

Thank you.

Tena Sakai
tsakai@gallo.ucsf.edu