You can create the following types of backups:
- Logical backups contain tables, stored procedures, and other logical data. You can extract logical data with an Oracle Database utility, such as Data Pump Export, and store it in a binary file on disk. Logical backups can supplement physical backups.
- Physical backups are copies of physical database files. You can make physical backups with Recovery Manager (RMAN) or operating system utilities.
When you use RMAN, you can store the following types of backup formats on disk:
- An image copy is a bit-for-bit, on-disk duplicate of a data file, control file, or archived redo log file. You can create image copies of physical files with operating system utilities or RMAN and use either tool to restore them. Image copies are useful for disks because you can update them incrementally and recover them in place.
- A backup set is a proprietary format that RMAN creates. It contains the data from one or more data files, archived redo log files, control files, or server parameter file. The smallest unit of a backup set is a binary file called a backup piece. Backup sets are the only form in which RMAN can write backups to sequential devices, such as tape drives. One advantage of backup sets is that RMAN uses unused block compression to save space in backing up data files. The backup set includes only those blocks in the data files that have been used to store data. Backup sets can also be compressed, encrypted, sent to tape. They can use advanced unused-space compression that is not available with data file copies.
RMAN can also interface with Media Management Library (MML) or System Backup to Tape (SBT) software, which can create backups to tape, Oracle Database Backup Cloud Service, or Zero Data Loss Recovery Appliance (commonly known as Recovery Appliance).