alphaspirit - Fotolia
There are some situations in which Oracle Recovery Manager (RMAN) isn't required for Oracle backups. The most obvious situation that comes to mind is that it is possible to back up a cold database (a database that isn't running) without using RMAN. If a database is not mounted, then the database can be backed up at the file level without any database-level tools being required.
Most organizations probably aren't regularly backing up cold databases. Even so, there is another situation that would warrant using something other than RMAN for Oracle backups. Organizations using older database releases may not be able to use RMAN at all.
According to Oracle, you can create an 8.x or 9.x recovery catalog schema in any Oracle database release 8.1.x or higher and a 10.0.1 or higher recovery catalog schema in any Oracle database release 9.0.1 or higher. Oracle goes on to say that the recovery catalog schema version must be greater than or equal to the RMAN client version. In other words, the oldest target or auxiliary database that can be backed up using the RMAN 8.0.6 client is database version 8.0.6. Older databases would not be supported.
It is possible with Oracle backups to use an older version of the RMAN client with a newer database, but even that has its limits. For example, if you need to protect a version 11.2.0 database, then the oldest RMAN client that you will be able to use is 126.96.36.199.
Furthermore, when using an older version of the RMAN client to protect a newer database, you will not be able to take advantage of some of the newer features. For example, when using the Oracle9i RMAN client to back up an Oracle Release 10g database, you do not have access to features like the fast recovery area, flashback database, TSPITR with an RMAN-managed auxiliary instance, or recovery through RESETLOGS.
Oracle RMAN support varies by vendor
RMAN improves database backup and recovery