IMS DEDB Fast Recovery scenario

This typical scenario demonstrates how IMS DEDB Fast Recovery can help you simplify and shorten your DEDB recovery operations.

Without IMS DEDB Fast Recovery, if an unscheduled IMS cold start becomes necessary, you must run the Database Recovery utility for all DEDB areas that were in use when IMS failed.

For each area to be recovered, the Database Recovery utility requires an image copy and either all of the IMS system OLDS, or the change accumulation data set created after the image copy was taken. Also, in the DEDB data-sharing environment, you must deallocate the system log data sets and DEDB areas from other active IMS subsystems.

With IMS DEDB Fast Recovery, you need only the system logs after the last complete checkpoint. IMS DEDB Fast Recovery can recover all necessary areas without interfering with the execution of the other active IMS subsystems in the same data-sharing environment. Also, IMS DEDB Fast Recovery eliminates the need to run the Log Recovery utility.

By subsequent execution of the Batch Backout utility for the DL/I databases and the MSDB Dump Recovery utility for the main storage databases, IMS DEDB Fast Recovery enables fast and efficient execution of an unscheduled IMS cold start while maintaining the integrity of the IMS databases.

For more information about IMS recovery procedures, see IMS recovery procedures.