Making Backups with RMAN
You can use the backup command to back up data files, archived redo logs, or control files. You can also use the backup command to make copies of data files and backups of backup sets. Because RMAN provides (since the Oracle9i Database release) the default configuration for all backup-related parameters, such as devices, formats, and tags, if you want you can back up your entire database by simply typing the command backup database at the RMAN prompt. You must, of course, first connect to the target database before backing it up, and the database must be in mount or open state if it’s running in archivelog mode and must be in the mount state if it’s operating in noarchivelog mode.