The Display Unique Key command displays the number of unique values in the
access path fields for a data keyed file (non source). The file does not have
to have unique keys. The system provides the number of unique values for the
first 4 key fields of a file. This means a count of the unique values for key
1, key 1-2, key 1-3, and key 1-4. One line is listed for each member. The
information can provide a better understanding of the data.