-603 A UNIQUE INDEX CANNOT BE CREATED BECAUSE THE TABLE CONTAINS ROWS WHICH ARE DUPLICATES WITH RESPECT TO THE VALUES OF THE IDENTIFIED COLUMNS AND PERIODS

Explanation
 The index that is defined in
the CREATE INDEX statement could not be created as unique because
the specified table already contains rows that are duplicates with
respect to the values of the identified columns and periods.

System action
 The statement cannot be processed.

Programmer response
 Examine the data to determine whether or
not the duplicate data is valid. Alternatively, consider creating
a nonunique index.

SQLSTATE
23515