Data recovery

Recovery is the rebuilding of a database or table space after a problem such as media or storage failure, power interruption, or application failure. If you have backed up your database, or individual table spaces, you can rebuild them should they become damaged or corrupted in some way.

There are four types of recovery:

• Crash recovery protects a database from being left in an inconsistent, or unusable, state when transactions (also called units of work) are interrupted unexpectedly.
• Disaster recovery consist of the process to restore a database in the event of a fire, earthquake, vandalism, or other catastrophic events.
• Version recovery is the restoration of a previous version of the database, using an image that was created during a backup operation.
• Rollforward recovery can be used to reapply changes that were made by transactions that were committed after a backup was made.

The DB2® database manager starts crash recovery automatically to attempt to recover a database after a power interruption. You can use version recovery or rollforward recovery to recover a damaged database.