secondary relationship

Usually, relationships are bi-directional, i.e. each relationship has an inverse relationship. One relationship property in such a pair can be marked as secondary, which indicates, that this relationship is usually automatically set. This concept is a soft concept, which does not influence the database consistency and might be changed at any time. Having parents and children as bi-directional relationships in person, one would define parents as secondary, when usually children are associated with its parents.

When usually allocating parents to the children, the parent relationship is set automatically and should be defined as secondary.