Coordinating Db2, OAM, and your application

OAM uses Db2 databases to contain descriptive information about every object that is stored. OAM does not commit the descriptive information written to that Db2 database; the application using OAM must perform that function. This allows the transaction to correlate and synchronize OAM’s activity with other activity in the application (for example, synchronization of an application’s and OAM’s permanent database changes, or alternatively, synchronization of backing out of those changes).

Note: When objects are stored directly to either the file system sublevel or the cloud level from an application program, the application must perform the Db2 commit within 24 hours of storing the object. Failure to do this ultimately results in loss of object data stored in the file system or cloud level.

Another example is an application transaction to perform an object update, something OAM does not support. That is, an object can be retrieved using OAM, updated by the application, original version deleted by OAM, new version stored by OAM with the original name, then committed as a permanent change by the application when it is satisfied with the results. If the application is not satisfied with the results, it has the option of preserving the original object by backing out all of the changes made by OAM up to that point.

Also, understand the OAM configuration established by the system programmer. In a classic OAM configuration, there is only one instance of OAM (an OAM subsystem and, optionally, an OAM address space) and an association with a single Db2 subsystem. However, a multiple OAM configuration can have multiple instances of OAM used to perform object processing. Each object instance of OAM (an OAM subsystem and, optionally, an associated OAM Object address space) in a multiple OAM configuration is associated with a unique Db2 subsystem. Therefore, in a multiple OAM configuration, your application might, depending on the operating environment, need to explicitly identify the Db2 subsystem to be used to process the application request. This Db2 subsystem identification directs the application request to the appropriate OAM instance for object processing.