1.88 DB_UNIQUE_NAME
DB_UNIQUE_NAME specifies a globally unique name for the database.
               
| Property | Description | 
|---|---|
| Parameter type | String | 
| Syntax | 
 | 
| Default value | Database instances: the value of  Oracle Automatic Storage Management instances:  | 
| Modifiable | No | 
| Modifiable in a PDB | No | 
| Basic | Yes | 
| Oracle RAC | Multiple instances must have the same value. | 
Databases with the same DB_NAME within the same DB_DOMAIN (for example, copies of a database created for reporting or a physical standby) must have a unique DB_UNIQUE_NAME. Every database's DB_UNIQUE_NAME must be unique within the enterprise.
                  
The value of DB_UNIQUE_NAME can be up to 30 characters and is case insensitive. The following characters are valid in a database name: alphanumeric characters, underscore (_), number sign (#), and dollar sign ($).
                  
Note:
DB_UNIQUE_NAME is used by several components within an Oracle instance to default file names or file paths, such as the default for the DG_BROKER_CONFIG_FILEn initialization parameter.  In these cases, on UNIX platforms, the dollar sign ($) character will be removed from the path or file name, because the character is used by Oracle to define the start of an environment variable substitution within a path or file name.
                     
Note:
As part of their operations, some database tools or utilities create a string that uniquely identifies a database. The string may include the DB_UNIQUE_NAME for a database, and other identifying information for the database, such as the database SID. Oracle Database restricts some identifiers to 30 characters, so using a short DB_UNIQUE_NAME can help prevent ORA-00972 "identifier is too long" messages from database tools and utilities that create a string that includes the DB_UNIQUE_NAME.
                     
See Also:
Oracle Data Guard Concepts and Administration and Oracle Database Administrator’s Guide for more information on setting this parameter