The listener is a software program that runs on each remote node and listens for any incoming database requests.
When a request is detected, the listener may direct the request to:
- A dedicated server
- A multithreaded server
- An existing process or pre-spawned shadow process
The following Slideshow illustrates what happens if the listener chooses to direct that request to an MTS:
When an Oracle database has been configured as a multi-threaded server, incoming connections are always routed to the dispatcher.
However, a dedicated connection can be specifically requested by having
SERVER=DEDICATED in the
CONNECT_DATA portion of the connect descriptor.
It is sometimes useful for transactions involving a high degree of activity to use a dedicated connection.
The next lesson discusses the architecture of MTS.