This section will discuss the core components required to handle Oracle connections.
A connect descriptor is used to define the service name and the location of the database. The address component of a connect descriptor defines the protocol, host name, and port number. Though port numbers can be between 1 to 65535, those from 1 to 1024 are usually reserved for special processes. The connect data component of the description describes the service to which you want to connect. If you do not include the instance_name in your descriptor, it will default to the Oracle SID if not defined.
A sample connect descriptor forlooks like the following:
(DESCRIPTION = (ADDRESS=(PROTOCOL=tcp) ...