Unique substitution masking ensures that each unique source value uses a unique dictionary value.

To mask a source value with a unique dictionary value, you can configure unique substitution masking. If a source value is masked with a specific dictionary value, then no other source value is masked with this dictionary value.

For example, the Name column in the source data contains multiple entries of

John

. If you configure repeatable masking, every entry of

John

takes the same dictionary value, such as

Xyza

. However, other source values might also be masked with the same dictionary value. A source entry

Jack

can also use the dictionary value

Xyza

. As a result, all entries of John and Jack use the same dictionary value. When you configure unique substitution masking, if all source values of

John

use the

Xyza

dictionary value, then no other source value uses the same dictionary value.

Unique substitution masking requires a storage connection for the storage tables. Storage tables contain the source to dictionary value mapping information required for unique substitution masking.