REF Relations

A REF Relation is only supported for those databases that have Object-Relational features and support the REF datatype.  A REF relation is automatically associated with a Column that has a datatype of REF and has been constrained to be scoped to a specific object table (similar to a traditional referential integrity constraint).   The REF Relation's parent Table is the referenced object Table and the Relation's child Table is the owner of the REF Column.

You can't create or delete a REF Relation.  It is automatically created and deleted based on the REF Column and its properties.  However, you can toggle the display of all REF Relations in the Diagram's Relation Display Options Property Page. You can also toggle the display of any individual Relation by selecting the Relation, then selecting the Graphic tab in the Property Browser, and toggling the Display checkbox.