Partial Backups (SAP Library - SAP Database Guide: Oracle (BC-DB-ORA-DBA))

Partial Backups

Use

You can reduce long backup times for your Oracle database by dividing the backup into several partial backups.

Features

Advantages

The partial backups require less time, so you can perform them daily.

You can recover the database at any time if the corresponding redo log entries exist. It is also possible to restore the entire database and then recover it.

You can quickly recover after a media error – that is, a disk crash – as you only need to restore the files of the affected hard disks.

Disadvantages

Restoring the entire database takes as long as the total of all of the partial backups. This situation only normally occurs with logical errors, such as program errors or user errors. However, this is an unlikely event.

You must ensure that all database files are saved in a partial backup cycle. This is your responsibility as database administrator.

Recommendation

Back up at tablespace level (not at database file level, which is also possible), as BRBACKUP can then make sure that all files from a tablespace are backed up.

Splitting extremely large tablespaces into several smaller tablespaces can be useful in this case. For example, you can put extremely large tables into separate tablespaces, and then back them up separately at tablespace level.

Use BRBACKUP command option -f|-fillup to do this.