You probably do not want to delete a relationship type if you already have relationship records that use the relationship type. If your relationship object uses the relationship type code column instead of the rowid column and you have records in that relationship object for the relationship type you are trying to delete, you will get an error.
The above warnings are not applicable to FK relationship types.You can delete relationship types that are associated with hierarchies. The confirmation dialog displays the hierarchies associated with the relationship type being deleted.
To delete a relationship type:
In the Hierarchies tool, acquire a write lock.
In the navigation tree, right-click the relationship type that you want to delete, and choose
Delete Relationship Type
.
The Hierarchies tool prompts you to confirm deletion.
Choose
Yes
.
The Hierarchies tool removes the selected relationship type from the list.