This box can only be checked if the Use Source column/transformation checkbox is checked. When the non mandatory source columns checkbox is selected QAD Data Warehouse Designer will process the load even when one or more of the source columns does not exist. In this way a super set of source columns can be selected across different versions of an application. If this option is chosen it may be advisable to set a default value via a transformation if the column is null. (see the section on handling missing source columns (on page 276)).