HALDB alter and batch processing when IMS manages ACBs
When IMS manages ACBs, batch application programs and batch utilities can access a HALDB database while the database is being reorganized by the HALDB alter function.
Ensure that the directory data set of the IMS catalog is available to any batch application programs or utilities that access the HALDB database that is being altered.
Batch application programs
Batch application programs can access a HALDB database while a HALDB alter operation is in progress.
When IMS manages ACBs, the offline batch application programs read the ACBs from the staging data set of the IMS catalog. Any specification of the IMS DD statement for the DLIBATCH procedure or the IMSACB, IMSACBA, and IMSACBB DD statements for the DBBBATCH procedure are ignored and can be omitted from the JCL.
Batch utilities
Batch utilities can access a HALDB database while a HALDB alter operation is in progress.
To alter a HALDB database offline, use the HD Reorganization Unload utility (DFSURGU0) and the HD Reorganization Reload utility (DFSURGL0). The HD Reorganization Unload utility automatically retrieves the active database records from the directory data set of the IMS catalog. When you use the HD Reorganization Reload utility to reload the database with the changed definition, by default, the reload utility obtains the active database from the directory data set of the IMS catalog. The altered database is in the staging data sets of the IMS catalog. You can specify the STAGING keyword on the DFSACBPD DD statement in the execution JCL to obtain the pending database from the staging data sets.