In pre-16.0 databases, you could create a super-user by granting them DBA authority. Users with DBA authority could perform any privileged task in the system. When you upgrade your database, any users that had DBA authority get the SYS_AUTH_DBA_ROLE compatibility role, and automatically receive exercise and administration rights for all roles and privileges that are present at the time of upgrade.

Also, when you create a new role and don't specify an administrator at creation time, users with the MANAGE ROLES system privilege (global administrators) can administer the role.

However, if you create a new role and assign administrators as part of role creation, administration is then limited to the grantees who were given administration rights. Therefore, if you want your super-user to have administrative rights for the new role, you must grant it explicitly.

 See also