Problem solve Get help with specific problems with your technologies, process and projects.

Levels for incremental backups in RMAN

We want to plan incremental backups on Oracle 9i with RMAN. How do I detemine what levels of incremental backups to use?

We want to plan an incremental backup on Oracle 9i with RMAN. How can I detemine the levels of incremental backups? In other words, when do I use level 2 or 3 or 4 or 000 or 9?
The first backup you should take is an incremental level 0 backup. The level 0 backup is the same as a full backup. You need a full backup as your base backup from which incremental changes are determined. A full RMAN backup (backup full database) cannot be used. RMAN will only use a level 0 backup as a base for other incrementals.

Once you have a level 0 backup, you can take an incremental backup. The incremental level can be any integer from 0 to 4. Most Oracle DBAs only use 0 to 2. If you take a level 2 incremental backup, it will back up any changes since the most recent level 2, 1 or 0 backup. A level 1 incremental backup will back up only those changes since the most recent level 1 or 0 backup.

The way that most Oracle DBAs use RMAN for incremental backups follows this guideline: take a level 2 incremental backup daily and a level 1 incremental backup weekly. The daily incremental backup will get all changes in the last day. The incremental level 1 backup will get all changes for the last week. Normally, an incremental level 0 is taken once a month. You may change the time periods to suit your specific needs.

Life gets better in Oracle 10g with the Incrementally Updated Backup (IUB). With IUB, you take a level 0 backup. A level 1 backup will modify the contents of the level 0 backup with the changes. This way, your level 0 backup is always up to date.

Dig Deeper on Oracle database backup and recovery