Re: 2 Day DBA Course: perception check

On Thu, 27 Jan 2005 09:23:33 -0900, "David E. Grove" <david_grove_at_correct.state.ak.us> wrote:

>I'm working through the 2 Day DBA Course for 10g.
>
>I notice that on p. 4-3 ("Configuring the Network Environment") the "Easy
>Connect Naming" is discussed. It states the the connect string is formed as
>follows:
>
>CONNECT username/password_at_host [:port] [/service_name]
>
>Then it supplies a specific example:
>
>CONNECT scott/tiger_at_my-server:1521/mydb
>
>
>
>My question: Since the service name already includes the port information,
>isn't the explicit inclusion of the port number in the example redundant?
>Wouldn't the following also be acceptable as a connect string:
>
>CONNECT scott/tiger_at_my-server/mydb
>
>
>
>Thank you.
>
>
>
>--
>David Grove
>
>- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>"I think not," said Descartes, and disappeared.
>
>

Nope. Services have nothing to do with the listener's port number.

The listener listens for incoming connections on a certain port number defined by the listener *only*. And this is only used for establishing the initial connection between the connecting client and the listener itself.. But as soon the concact to the listener has been established correctly, the port number is out of play. The further processing regarding passing on connections to the services registered with the listener is totally independent on the listeners port number.

Think of the port number as a phone number. A teacher calls a father to tell him of his lazy son. The teacher hangs up and the following shouting in the house is absolutely independent on which number the teacher called. The teacher still had to know the right number in order to start the shouting, though. And you still have to specify the port number when connecting...

• Kenneth Koenraadt