Switches That Start and Stop Databases
The 
-gd option lets you limit the users who can
                                start or stop a database on a running server to those with a certain
                                level of privilege in the database to which he or she is already connected:
- DBA –
                                                (default value) only users with
                                                SERVER
                                                OPERATOR system privilege can start an extra
                                                database.
 
- ALL –
                                                (default in start_iq and
                                                  default.cfg) any user can
                                                start and stop databases. This setting means that
                                                the DBA does not need to issue START DATABASE commands.
                                                Users still need the privileges to access a
                                                particular database once he or she has started it. 
 
- NONE
                                                – no one can start or stop a database from
                                                Interactive SQL on a running server.
 
                         
Note: If -gd ALL is not set when you start the
                                        server, only
                                        a
                                        user with the SERVER OPERATOR system privilege can start
                                        additional databases on that server. This means that users
                                        cannot connect to databases that are not already started,
                                        either at the same time as the server, or since then by
                                        a
                                        user with the SERVER OPERATOR system privilege. However, it
                                        also lets
                                        a
                                        user without the SERVER OPERATOR system privilege stop a
                                        database. For this reason, you may want to change this
                                        setting to DBA on production databases.