David Gilbert <dgilbert(at)velocet(dot)ca> writes:
> I find that the whole database dumps do not have 'create user' and
> 'create group' commands.
Those are dumped by pg_dumpall, but not by pg_dump. Since users and
groups span all databases in an installation, it wouldn't be very useful
for pg_dump to include them in its (per-database) output.
regards, tom lane