Backup Overview (SAP Library - SAP Database Guide: Oracle (BC-DB-ORA-DBA))

Backup Overview

This section gives you basic information to develop a careful approach to backing up your Oracle database. For more information on the reasons for database backup, see Why Back Up the Database?

Prerequisites

When designing your approach to backup, archive, and recovery, consider the following:

You design an approach based on the needs of your company. You ask yourself questions such as:

What level of availability do you require from the database?

How long can you afford to shut down the SAP System in the event of data loss? Some backup approaches require a longer restore and recovery time than others.

Can you afford to lose data at all? If not, consider high availability solutions for Oracle such as Oracle standby databases.

You carefully test your approach before your SAP System goes live, and again after any changes have been made to the approach.
You document your approach in a plan and make sure that all relevant people know the procedures to follow in the event of problems.

Process Flow

You identify what needs to be backed up.

Normally, you back up the complete database and the redo log files.

You identify the database backup type that you require.

Normally, you perform an online and complete backup.

We recommend performing at least one offline backup per cycle, more often (for example, weekly) if possible. Only use incremental backup for larger databases.

You work out a backup cycle. We recommend a minimum cycle of 14 days, although 28 days is preferable. For example, with a 28-day cycle, you reuse the backup media after 28 days.

You schedule regular backups.

Recommendation

We strongly recommend you to schedule regular backups with the DBA Planning Calendar, using the action patterns available there. There are action patterns for different requirements to cover the main aspects of database administration, including backup.

You verify the:

Backup tape readability, that is, a check on the contents of the media after the backup
Database block consistency, that is, a check on the database itself

If possible, run both types of verify daily, otherwise weekly. At the least, be sure to run a verify once in each backup cycle.

You can back up the database and then verify both the backup media and the database using a single BRBACKUP command, brbackup -w use_dbv. This option is also available in the action patterns of the DBA Planning Calendar. Be aware that a verify considerably extends backup run times.

To only verify database block consistency (that is, without a database backup), use the command brbackup -w only_dbv.

To verify the backed up redo log files, use the command brarchive -w|-verify.

Result

See the following for examples of backup approaches:

Backup Approach with Daily Complete Backups

Backup Approach for Very Large Database with Partial Backups

Backup Approach with Retention Period Zero