HALDB partition names and numbers

Each HALDB partition has a name, an ID number, a change version number, and a reorganization number. You define the partition name and IMS assigns and manages the numbers.

The partition ID numbers, change version numbers, and reorganization numbers are critical to the management of HALDB partitions by IMS and to the integrity of the data that the partitions contain.

In addition to being stored in each partition record in the RECON data set, these numbers are also stored in the HALDB master database record. IMS uses the numbers in the HALDB master database record to help manage the partitions and to access the data that the partitions contain.

If you delete a HALDB master database record, the partition numbers it contains are lost and the partitions associated with the deleted HALDB master database record can no longer be accessed. The partition numbers cannot be reproduced by redefining the HALDB master database record.

Deleting a HALDB master database record can also result in the loss of access to data in logically related HALDB databases, because the extended pointer set (EPS) of the logically related segments becomes invalid when the partition ID and reorganization number of the target segments are lost.

For these reasons, never delete a HALDB master database record from the RECON data set unless you are permanently deleting the HALDB database and all of its data, as well as all references to the HALDB database being deleted that are in any logically related or secondary index databases.