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[lakekids]

We have a VSAM KSDS file with alternate indexes defined. The alternate indexes have unique keys and they are defined as upgrade. The alternate index files were defined to the FCT as Read and Browse only even though the base cluster was defined as Read , Add, Update, Delete, Browse.

We had a problem where it appeared that the alteranate index was acting more like an ESDS file than a KSDS. For example I would add 5 records (in a row) using the primary key (numeric id) via the base cluster. After each add I would read the file using the alternate index to get a list of all records on the file in name sequence (alternate index). Everything worked fine until I added the 6th record. Then when I read using the alternate index it would no longer find all the records on the file. The only way to get the alternate index read to work properly at that point was to close and reopen the files.

At first I thought the problem might be a buffering issue and I updated the file definition to increase the buffersize. However, this did not fix the problem.

I changed the alternate index files to add, update, delete and since then I have not had a problem.

However, I know that we have numerous files with alternate indexes where the alternate is NOT set to ADD, UPDATE, DELETE (even though the base cluster is) and there have been no problems reported on those files.

I have attempted to search the CICS manuals for information concerning these parameters and the affect on VSAM alternate indexes.

Questions:

1. If the base is set for add, update, delete then should the alternate indexes be defined that way also? (That makes sense to me).

2. My confusion is why the anamoly - works sometimes but not others?

3. Why does adding a record not cause an error when the alternate index is set to upgrade, read, browse and the base is set to read, add, update, delete?