Init.ora - service_names / tnsnames.ora

Question

From what I understand - by using the SERVICE_NAMES parameter in the init.ora file , you can specify alias/new instance name for a database , which is automatically detected by the listener. And would not require updates to the TNSNAMES.ORA file.
So normally and in tnsnames.ora I have a instance called TRN. In the init.ora file I have
service_names = trn.world,trn_test.world
But this is not working. I can connect to trn but not trn_test. Is my understanding of this parameter wrong?
or am I doing something wrong?
thanks in advance.

Answer 1

SERVICE_NAMES
Parameter type
String
Syntax
SERVICE_NAMES =
db_service_name [, db_service_name [,...] ]
Default value
DB_NAME.DB_DOMAIN if defined
Parameter class
Dynamic: ALTER SYSTEM
Range of values
Any ASCII string or comma-separated list of string names
SERVICE_NAMES specifies one or more names for the database service to which this instance connects. You can specify multiple service names in order to distinguish among different uses of the same database.
For example:
SERVICE_NAMES = sales.acme.com, widgetsales.acme.com
You can also use service names to identify a single service that is available from two different databases through the use of replication.
In an Oracle9i Real Application Clusters environment, you must set this parameter for every instance.
If you do not qualify the names in this parameter with a domain, Oracle qualifies them with the value of the DB_DOMAIN parameter. If DB_DOMAIN is not specified, Oracle uses the domain of your local database as it currently exists in the data dictionary.
See Also:
Oracle9i Net Services Administrator's Guide for more information on this parameter and its settings
"DB_DOMAIN"
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96536/ch1186.htm#REFRN10194
Joel P�rez