We are using SEQLOV function for masking card numbers using seedlist and cross-referencing. We encountered duplicate use of the seedlist record when we run masking for the 2nd file where some of the cards are not yet present in the XREF file. 

We are expecting that when we run the masking job for the 2nd file, all the cards that are not yet in the XREF file will add new entries in the said file using different value from the seedlist file. But what happened during testing was, when the masking for the 2nd file was submitted, the card number used to replace the new cards are already used. It seems like the SEQLOV function, restarted searching/assigning values from the top of the seedlist file. 

Kindly explain and let us know how the SEQLOV function should behave.

Release : 99.0

Component : CA Test Data Manager

   Basically, SEQLOV function masks the column values with sequentially selected values from a seed list. when sequenctial look up in seed list ends, values will be picked from the bigining of the seedlist. So, there is no guarenty that, it maintains consistency.

   When you use cross reference file, before FDM apply the masking, it will look for old value in reference file. if old value present in file, new value from reference file will be returned as masked value and masking function will not be applied. 

  In your case, masking happened correctly on File1. And in File2, whenever there is no lookup value present in reference file, it applied the SEQLOV function to pick values from the seedlist. So, first value in seedlist has returned and also added entries in reference file. Which is causing duplicate entries.