If
you need to modify the data types or lengths for any source columns or fields, use the
Advanced editor for the component and only make changes to the Output columns.
Do not make changes to the External columns. If you make changes to both the
External and the Output columns, the changes will be lost the next time you
open the editor for the source component.
If done correctly, you will be able to use the “Refresh” button to see any new columns or fields and your previous changes to other columns will remain intact.