V$DATAGUARD_CONFIG displays the unique database names defined with the DB_UNIQUE_NAME and LOG_ARCHIVE_CONFIG initialization parameters, providing a view of the Oracle Data Guard environment from any database in the configuration.
The first row of the view lists the unique database name of the current database that was specified with the DB_UNIQUE_NAME initialization parameter. Additional rows reflect the unique database names of the other databases in the configuration that were specified with the DG_CONFIG keyword of the LOG_ARCHIVE_CONFIG initialization parameter.
Unique database name
DB_UNIQUE_NAME of the parent database, also known as the database that supplies live redo to the destination.
For example, suppose Boston is the DB_UNIQUE_NAME of the primary database, Chicago is the DB_UNIQUE_NAME of the Far Sync Instance, and Seattle is the DB_UNIQUE_NAME of the terminal standby database. Since Boston is the primary database, it has no parent database so the PARENT_DBUN for Boston will be NULL. Since Boston services Chicago, the PARENT_DBUN of Chicago will be Boston. Since Chicago services Seattle, Chicago will be the PARENT_DBUN for Seattle.
Type of archival destination database:
LOCAL - Local to primary database
PHYSICAL - Physical standby
FAR SYNC INSTANCE - Far Sync Instance
CROSS-INSTANCE - An instance of the primary
LOGICAL - Logical standby
SNAPSHOT - Snapshot standby database
DOWNSTREAM - Streams downstream capture database
The SCN up to which the specified database has applied redo
The ID of the container to which the data pertains. Possible values include:
0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data