CICS VSAM Transparency for z/OS, Version 1.2


Creating the appropriate DB2 indexes

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:

This graphic shows a row representing the layout of the record. There are four cells in the row that are all different sizes. The first cell contains the number 6, indicating the ITEM-NUMBER field. The second cell is longer and empty. The third cell contains the number 3, indicating the ITEM-SUPPLIER-CODE field. This is the shortest cell. The fourth cell is empty.

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.





Last updated: December 6, 2013 20:43:7

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Timestamp icon Last updated: Friday, 6 December 2013


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