An Introduction to IMS: Your Complete Guide to IBMs Information Management System

Database recovery is normally performed only when there has been a failure of some sort. Most of the time recovery is done as a result of a system, hardware, or application failure. However, you can also use recovery procedures to return a database to a previous point in time, and to recover from application logic failures.

In general, a database might need to be recovered under the following circumstances:

• A DB batch update job fails after making at least one database update.

• A failure occurs on a physical DASD device.

• A failure occurs in a database recovery utility.

• A failure of a dynamic backout or a run of the Batch Backout utility (DFSBBO00) has occurred.

• An IMS online system failure and emergency restart has not been completed.