Can I have oracle database service name without SID?

Question

In general, Oracle Database SID included in Service name. For Ex: SID: orcl & Service Name: orcl.mycomp.com

So, It is possible to define the service name without including SID Ex: mydb.mycomp.com for database SID is orcl.

Answer 1

The SID is the identifier for the database, but the service_names are the names for the services that it provides, and can be functional rather than technical.

So you might have a database that provides invoice services, sales services, message services, and set up service_name appropriately. This has the advantage that the listener can then choose the appropriate database to connect to based on the requested service, and a single service can be available from multiple databases (via replication).

You can also move services from one database to another, and monitor service activity through v$session and v$sql.

Have a look at this as well: http://www.ardentperf.com/pub/services-schneider07.pdf

Answer 2

If you have a SID of orcl, you can set the service name to mydb.mycomp.com by setting the Oracle system parameter SERVICE_NAMES in the orcl database:

ALTER SYSTEM SET service_names = 'mydb.mycomp.com';

or, if you want to also keep orcl as a service name:

ALTER SYSTEM SET service_names = 'orcl,mydb.mycomp.com';