Oracle Recovery Manager (SAP Library - SAP Database Guide: Oracle (BC-DB-ORA-DBA))

Oracle Recovery Manager

Use

The Oracle Recovery Manager (RMAN) is an Oracle backup program. You can use it as a command line interface (CLI) or as a graphical user interface (GUI) in the Oracle Enterprise Manager (OEM). We support RMAN with the SAP backup tools BRBACKUP and BRARCHIVE.

RMAN uses the System Backup to Tape (SBT) interface to back up to tape devices. We implement SBT using the SAP backup library. External backup tools can implement this interface as a dynamic link library (DLL).

Integration

By integrating RMAN into BRBACKUP, you can add security and flexibility to important functions in existing backup strategies and tools:

The recovery catalog is not used. The backup information is stored in the control file. After the backup, the control file is also backed up. In a restore, the control file is restored first, followed by the data files.

The integration of RMAN into BRBACKUP also guarantees integration into the SAP Computing Center Management System (CCMS).

BRBACKUP tape management functions as previously (that is, as when using the SAP backup library).

You can still use the BACKINT interface with external tools.

The SAPDBA user interface remains unchanged, except for some new options.

All previous SAP backup strategies are supported while using RMAN. Nevertheless, RMAN is not supported for standby database backups and split-mirror backups.

The following components are delivered with the standard Oracle8 installation:

RMAN with the Oracle SBT interface
Backup library and backup tool Networker from Legato
Legato’s BACKINT interface implementation (as of Oracle 8.0.5)

The SAP installation also delivers the SAP backup library with BRBACKUP and BRARCHIVE.

You can integrate RMAN into your Oracle database with the SAP System using one of the following:

SAP implementation

You can use the SAP implementation of the Oracle interface SBT, using the SAP backup library. For more information on activating the SAP backup library, see SAP Note 142635.

Legato implementation

You can use the Legato implementation or other external backup libraries. These solutions differ in the backup media that they support and the characteristics of the backup programs used.

Prerequisites

You are subject to the following restrictions when you use RMAN directly, that is, using the CLI or GUI in the OEM:

RMAN places information about backups in a recovery catalog. For security reasons, this catalog is held in a separate database on a separate host. This means more administrative work.
Restore or recovery is complicated in a disaster situation in which you lose your production database and recovery catalog. It is often only possible with the help of Oracle Support. Without the recovery catalog data, RMAN cannot recover the database automatically using previous backups.
The database user making the backups currently needs the SYSDBA authorizations. SYSOPER authorizations are not sufficient.

Features

Incremental backups

This allows you to change your previous backup strategy and considerably reduce the amount of data to be backed up.

Consistent backups

Logical database block errors are recognized automatically during the backup. This makes sure that each backup is consistent. This function replaces the weekly check with DBVERIFY.

Reduction in amount of data backed up

Any database blocks that have never been used are not backed up.

Verify of backups

You can verify backups to tape with the RMAN VALIDATE command.

Reduction in redo log information

The command BEGIN/ END BACKUP is not needed in online backups, since the blocks are checked to see if the data is consistent.