1.2. RMAN Usage Considerations

RMAN backup is a physical backup method that was first developed with Oracle 8 and has steadily improved with each Oracle release. If you are going to use RMAN, you can use disk or tape. If you are using tape, a third-party media management library is needed to interface with your tape hardware.

There are two other methods of backup and recovery in the Oracle database: user-managed and the Oracle EXPORT utility. User-managed backups are essentially customized scripts that interact with the operating system capabilities such as copy and compress commands. These types of backups have been the mainstay of Oracle backups prior to and during the initial release of RMAN.

The EXPORT utility executed with the exp executable is essentially a logical backup utility that performs backups only on the logical components of the database. A logical backup consists of backing up the database at the tablespace level or backing up other logical database components such as a table. A physical backup consists of backing up the database files such as the datafiles, control files, and redo logs. This is one of the reasons EXPORT is typically not considered a stand-alone backup method but provides additional backup protection for RMAN or a user-managed backup.

RMAN performs many recovery options that are not supported by other available backup and recovery methods. Table 1.1 compares the capabilities of each backup method.

Starting the RMAN utility is a very straightforward process. To start RMAN, you need to be at the command line at the operating system level. In the case of a Windows environment, you would be at the DOS prompt.