Recovery facilities

Dynamic backout, batch backout, and forward recovery facilities are different in data-sharing and nonsharing environments.

Dynamic backout
As in a nonsharing environment, an online IMS system in a data-sharing environment dynamically backs out an application program's uncommitted database changes and discards its uncommitted output messages if the application program fails or requests backout with a rollback call. In a data-sharing environment, however, IRLM locks and RECON status indicators ensure integrity by protecting uncommitted changes from sharing IMS systems.
Batch backout
If the failing application program is a batch updater involved in block-level data sharing, IMS does not always automatically back out its uncommitted database changes.
Forward recovery
Recovery of a database in a data-sharing environment is similar to recovery in a nonsharing environment. In both environments, use the Database Recovery utility (DFSURDB0) and give it the most recent image copy of the database, along with all pertinent log data sets used since you made that image copy.

Parent topic: Recovering from failures