Use the following rules and guidelines for substitution masking:
If a storage table does not exist for a unique repeatable substitution mask, the session fails.
If the dictionary contains no rows, the Data Masking transformation returns an error message.
When the Data Masking transformation finds an input value with the locale, dictionary, and seed in the storage table, it retrieves the masked value, even if the row is no longer in the dictionary.
If you delete a connection object or modify the dictionary, truncate the storage table. Otherwise, you might get unexpected results.
If the number of values in the dictionary is less than the number of unique values in the source data, the Data Masking Transformation cannot mask the data with unique repeatable values. The Data Masking transformation returns an error message.