When an application program issues a call to a VSAM data set using an alternate index path, the CICS® VT DDM SQL is predicated on the columns that correspond to the path key. For example, the layout of the record for the sample file as shown in the copybook is as follows:
To access this file using the alternate index path, CICS VT uses the following predicate:
WHERE ITEM_SUPP_CODE =:host variable.
You must create a DB2® index on the column or columns that correspond to the alternate key. In this example, the field ITEM-SUPPLIER-CODE is mapped to the single DB2 column ITEM_SUPP_CODE.