RE: 10.2 listener won't start on same port as 9.2 listener

"I was talking about if a brand new database was created. The listener.ora file still needs an entry for that database."

No, it doesn't.

Read this (from http://download-west.oracle.com/docs/cd/B10501_01/network.920/a96580/listener.htm#490265):

For Oracle9i and Oracle8i databases, the listener uses the dynamic service information about the database and instance it has received through service registration before using statically configured information in the listener.ora file. Dynamic service registration is configured in the database initialization file. It does not require any configuration in the listener.ora file.

To ensure service registration works properly, the initialization parameter file should contain the following parameters:

SERVICE_NAMES for the database service name INSTANCE_NAME for the instance name
For example:

SERVICE_NAMES=sales.us.acme.com
INSTANCE_NAME=sales

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