>>how do i grant permissions on a database?
>
> You don't. Rights and privs are GRANTed on database objects.

Which means that permissions on these objects can be granted
by SYSDBA or by object owner (which can be sombody else
than database owner).

Ivan

>
>>who can grant permissions on a database?
>
> Initially, the Owner of the database and SYSDBA. It is possible for
> those users to hand on the privilege of GRANTing privileges (WITH
> GRANT OPTION).