ASA Database Administration Guide
  Running the Database Server
    Stopping the database server

Who can stop the server?

When you start a server, you can use the -gk option to set the level of permissions required for users to stop the server with dbstop. The default level of permissions required is DBA, but you can also set the value to all or none. (Interactively, of course, anybody at the machine can click Shutdown on the server window.)