Database Backup Types

Definition

This section describes the different types of backup that you can make of your Oracle database.

The term "backup" normally refers to a physical backup, which is sometimes called an image backup.

Oracle and SAP support the following types of database backup:

?      Physical backup using BRBACKUP

Physical backups, sometimes called image backups, are complete block-for-block copies of the database, either online or offline. Physical backups are required to recover the database to a consistent and current state. You can perform the following kinds of physical backups:

0       Online and offline backups of the database

0       Consistent online backups, that is, while the database is in use

0       Complete backups of the entire database

0       Incremental backups of only data that was changed since the last full backup

0       Tablespace backups to separately back up intensively used tablespaces between complete backups – this is an advanced function to speed up recovery, which we do not normally recommend.

0       Partial backups to back up only parts of the database, not the entire database.

?      Logical backup using BRSPACE – also called export

BRSPACE export uses the Oracle export and import functions to let you back up and recover specific objects – that is, a set of database records – in the database. However, logical backups are not a suitable replacement for physical database backups because you can only recover the database to the condition at the time of the backup. You cannot recover database changes made after a logical backup.

SAP tables are usually used by multiple users or applications, which means that it is not a good idea to make user-related backups with Export/Import. For example, you do not want a user to restore the ATAB table in order to retrieve lost entries in a particular SAP pool table stored in ATAB.

Logical backups of SAP objects can be performed using the SAP tool R3trans. R3trans exports SAP System objects (among others) from the database into operating system files. If a user then inadvertently deletes an object, that object can be imported from the exported backup file. For more information, see the documentation on Transport Tools.

There are also the following types of non-database backup:

?        Backup of executable programs and other components of the SAP System, described in What Needs Backing Up?

?        Operating system backup – for more information, see the documentation for your operating system