work of tnl listener in oracle 9i
It listens to the request of user connecting to the machine hosting oracle database and
(i)If the Shared server process (MTS) is being used ,the listener sends the user process to another process called the Dispatcher process ,which is already running in the server.
(ii)If dedicated server are being used ,the listener tells oracle to generate a new dedicated server
and then assigns the user process, to that dedicated server.
