To identify potential data quality issues, create a primary key profile that discovers non-unique rows. A primary key discovery profile is also useful when the primary key is a combination of columns that uniquely defines a row. Non-conforming rows might contain duplicate information. After you discover potential keys in a table, you can add the keys to the source table in a project.
For example, an Employee table contains an EmpID column. The value of the column is 100% unique. A primary key profile identifies the column as a possible primary key that you can add to the table in the project.