HALDB alter and batch processing when ACB libraries are used

Batch application programs

Batch application programs can access a HALDB database while a HALDB alter operation is in progress without requiring any changes to their existing execution JCL. However, until the online change function completes the alter operation when ACB libraries are used, IMS still requires the original, unaltered database definition for comparison purposes, even if all of the segment data in the database already conforms to the new database definition. Consequently, DLIBATCH application programs must reference the DBD library that contains the original, unaltered DBD on the IMS DD statement in the execution JCL. DBBBATCH application programs must reference the active ACB library that contains the original, unaltered database definition on the IMSACB DD statement. If you have dynamic allocation of the staging ACB library enabled, a DD statement for the staging ACB library that contains the new, altered database definition is not required.

Batch utilities

Batch utilities can access a HALDB database while a HALDB alter operation is in progress. However, until the online change function completes the alter operation when ACB libraries are used, IMS requires the original, unaltered database definition for comparison purposes, regardless of whether some or all of the segment data in the database already conforms to the new database definition.

Consequently, the IMS DD statement in the execution JCL for the utility must reference the DBD library that contains the original, unaltered database definition until online change is performed.

If you have dynamic allocation of the staging ACB library enabled, a DD statement for the staging ACB library that contains the new, altered database definition is not required.

If the HD Reorganization Reload utility is used to complete the reorganization of one or more partitions in a HALDB database for which the HALDB alter function was started, but the online change function has not been performed to complete the alter process, the execution JCL of the HD Reorganization Reload utility must include an IMS DD statement that references the DBD library that contains the original, unaltered DBD.