V$BACKUP displays the backup status of all online datafiles.

Column Datatype Description
FILE# NUMBER File identifier
STATUS VARCHAR2(18) File status: NOT ACTIVE, ACTIVE (backup in progress), OFFLINE NORMAL, or description of an error.

NOT ACTIVE indicates that the file is not currently in backup mode (that is, an ALTER TABLESPACE ... BEGIN BACKUP or ALTER DATABASE BEGIN BACKUP statement has not been issued), whereas ACTIVE indicates that the file is currently in backup mode.

CHANGE# NUMBER System change number when backup started
TIME DATE Time the backup started