|Default value||The instance's SID
Note: The SID identifies the instance's shared memory on a host, but may not uniquely distinguish this instance from other instances.
|Range of values||Any alphanumeric characters|
In a Real Application Clusters environment, multiple instances can be associated with a single database service. Clients can override Oracle's connection load balancing by specifying a particular instance by which to connect to the database.
INSTANCE_NAME specifies the unique name of this instance.
In a single-instance database system, the instance name is usually the same as the database name.