Improving database availability

Improving database availability in a data-sharing environment involves controlling online change, reorganizing databases, and making database image copies.

Controlling online change
If you modify a shared database online in a sharing environment, you must coordinate the sequence of /MODIFY commands across all sharing IMS systems.
Reorganizing databases
While you reorganize a database (using the database reorganization utilities), you must protect it from changes by IMS systems that are authorized to use it, unless you are using HALDB Online Reorganization (OLR).
Making an online database image copy
When you schedule the Online Database Image Copy utility (DFSUICP0) as a BMP, DBRC manages the requirement for restrictive access. You must, however, ensure that no IMS online systems, online or batch, other than the IMS online system running the Image Copy BMP, is authorized to update the database.

Parent topic: Data sharing in IMS environments