Database resgister with listener

Question

Hi,
can one or more databases register with single listener?
if we want to create second listener in the server then does we need to change port number or can we use default port number? please help me.
thank you!

Answer 1

851707 wrote:
Does it mean for different databases does we have different port numbers?The port is used by the listener, not by the database. One single listener, with the default name of LISTENER, listening on one single port, is quite capable of - was designed to - service multiple database instances of multiple versions running from multiple homes. Trying to create multiple, separate listeners for each database instance makes as much sense as the telephone company building separate switchboards for each customer.
Pavan's example showed you how a single listener could listen on two ports. Further, it showed how the single listener could have static registration of two instances. There is nothing in that configuration that would bind a database to one of the ports.
The database doesn't even use that port. Only the listener uses it (well, that and the client placing the request on that port for the listener to pick up). Once the listener gets the request, it spawns a server process to talk to the client, and assigns that connection (between the client and the server process) to a different port. Once the server process is spawned, the listener (and its ports) is out of the picture. You could even kill the listener and all existing connections would carry on, totally oblivious to the loss of the listener.