Oracle Backup Basics

Oracle backups can be taken at the physical level (hot or cold) or at the logical level. A physical backup is composed of the following:

Datafiles

Controlfiles

Archived redo log files (if the database is in ARCHIVELOG mode)

Parameter files (init.ora and SPFILE)

A physical backup is performed by taking an operating system copy of these files. Alternatively, RMAN can be used to accomplish the backup of the database files, with the exception of the init.ora file. It is a well-known fact that online redo logs need not be backed up, irrespective of the fact that a database is in ARCHIVELOG mode or NOARCHIVELOG mode. For detailed information on this topic and other basics mentioned in this chapter, refer to the Oracle 11g Backup and Recovery Concepts User’s Guide.