HALDB alter and offline when ACB libraries are used

Before you start the offline reorganization, access to the database must be stopped by issuing either the IMS type-2 command UPDATE DB NAME(partition_name) STOP(ACCESS) command or the IMS type-1 command /DBRECOVERY.

An offline reorganization is performed by unloading the database with the HD Reorganization Unload utility (DFSURGU0) and then reloading the database with the HD Reorganization Reload utility (DFSURGL0).

The HD Reorganization Unload utility automatically unloads the records from the active portions of both the A–J and M–V data sets. The IMS DD statement in the execution JCL of the HD Reorganization Unload utility must reference the DBD library that contains the original, unaltered DBD of the database, regardless of whether some or all of the database segments have been altered by the HALDB alter function.

The execution JCL for the HD Reorganization Reload utility (DFSURGL0) also must contain an IMS DD statement that references the DBD library that contains original, unaltered DBD of the database.

The altered DBD is in the staging ACB library. If you have dynamic allocation enabled for the staging ACB library, a DD statement for the staging ACB library is not required for either utility.

The HD Reorganization Reload utility loads all records into the A–J data sets. If the HALDB alter function was writing to the M–V data sets, the characteristics of the A–J data sets might not be correct. Before you reload the database, ensure that the A-J data sets are allocated enough storage for the altered segment sizes and, if you are altering VSAM data sets, that the VSAM CI sizes of the A–J data sets are correct.

After the database is reloaded, perform the online change function to enable the altered database in the online system and to reset the HALDB alter flags and counters in the RECON data set.

After online change is performed, you can restart the database.