The single field validation and relations are related as follows:

If single field validation is active for a table object, the system only exports fields from the table object that have changed.

There are often close relationships between individual fields in a table in the SAP System. This means that the fields are only meaningful together. For example, an employee’s personnel subarea data is only meaningful if the personnel area to which the personnel subarea is assigned is also known.

To meet this requirement, you can use the Interface Toolbox to define relations between two or more fields. If at least one field that is linked to one or more other fields by the Relations function changes, then the system exports all linked fields again.