Shutting Down Specific Dispatcher Processes

With the ALTER SYSTEM statement, you leave it up to the database to determine which dispatchers to shut down to reduce the number of dispatchers. Alternatively, it is possible to shut down specific dispatcher processes. To identify the name of the specific dispatcher process to shut down, use the V$DISPATCHER dynamic performance view.

SELECT NAME, NETWORK FROM V$DISPATCHER;

NAME  NETWORK
----- ---------------------------------------------------------------------------
D000  (ADDRESS=(PROTOCOL=tcp)(HOST=ocs.com)(PORT=37348))

D001  (ADDRESS=(PROTOCOL=tcp)(HOST=ocs.com)(PORT=37350))

Each dispatcher is uniquely identified by a name of the form Dnnn.
To shut down dispatcher D002, issue the following statement:

ALTER SYSTEM SHUTDOWN IMMEDIATE 'D001';

The IMMEDIATE keyword stops the dispatcher from accepting new connections and the database immediately terminates all existing connections through that dispatcher. After all sessions are cleaned up, the dispatcher process shuts down. If IMMEDIATE were not specified, the dispatcher would wait until all of its users disconnected and all of its connections terminated before shutting down.