superuser equality

I'd like to have a DB client connect using a username ('psuedodba')
different from the creator/owner ('dba') of the DB and its tables, but
still have that username be able to do everything the creator/owner can do
(alter tables, drop databases, etc). It appears that

"createuser -d -a psuedodba"

works for this purpose. Are there circumstances where 'psuedodba' lacks
powers that 'dba' has to create/destroy/alter/update/insert/delete? Or are
they truly equivalent in powers?

TIA.

Ed