Why and when should I backup my database?

Backup and recovery is one of the most important aspects of a DBA's job. If you lose your company's data, you could very well lose your job. Hardware and software can always be replaced, but your data may be irreplaceable!

Normally one would schedule a hierarchy of daily, weekly and monthly backups, however consult with your users before deciding on a backup schedule. Backup frequency normally depends on the following factors:

• Rate of data change/ transaction rate
• Database availability/ Can you shutdown for cold backups?
• Criticality of the data/ Value of the data to the company
• Read-only tablespace needs backing up just once right after you make it read-only
• If you are running in archivelog mode you can backup parts of a database over an extended cycle of days
• If archive logging is enabled one needs to backup archived log files timeously to prevent database freezes
• Carefully plan backup retention periods. Ensure enough backup media (tapes) are available and that old backups are expired in-time to make media available for new backups. Off-site vaulting is also highly recommended.

Frequently test your ability to recover and document all possible scenarios. Remember, it's the little things that will get you. Most failed recoveries are a result of organizational errors and miscommunication.