You can use the Database Manager GUI to change the server authorizations of the database system administrator (SYSDBA user).
The user has the managing DBM operators (user management) server authorization.
1. Choose Instance ® Configuration ® DBM Operator... .
2. Select the database system administrator.
3. Choose Properties.
4. On the Server Rights tab page, you can now extend or limit the server authorizations of the selected user by selecting or deselecting the required authorizations.
The server authorizations of the database system administrator are set according to your wishes.
Concepts of the Database System, Server Authorizations for the DBM Server,