A number of minor operational limitations are imposed by
this solution.
- The control record must be the very first record in the file.
The exit assumes the key is LOW-VALUES.
- The control record is never deleted. It is only read or updated.
- The control record must be manually migrated to the control record
table. Ideally, DB2® RI should
be used to ensure that neither the dummy control record in HLL_ITEM
nor the actual control record in HLL_ITEM_CONTROL is deleted.
- A record with a key of LOW-VALUES must exist in the main table
(HLL_ITEM). The record is generated by the exit during the initial
data migration.