The client applications
will still be able to reach the database, and no application changes will be
required.
Oracle Net supports the notion of service names, or aliases. Clients provide a service
name or Oracle Net alias to specify which database they want to reach without having
to identify the actual machine or instance for the database. Oracle Net looks up
the actual machine and the Oracle instance, using the provided service name, and
transparently routes the client to the appropriate database.
Resolving Oracle Net Service Names
The following Oracle Net configuration options resolve the service name the client
specifies into the host and instance names needed to reach an Oracle database:
Local name resolution
For local name resolution, you install a file called TNSNAMES.ORA on each client
machine that contains entries that provide the host and Oracle instance for
each Oracle Net alias. Youmu st maintain this file on the client machines if any
changes are made to the underlying database locations. Your network topology
is almost certain to change over time, so use of this option can lead to an
increased maintenance load.
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