Consistency checks applied during relation line placement
System Architect applies several consistency checks when you draw a relation line on a diagram. These checks are designed to ensure that your model can be implemented in a database.
Illegal relationships
•Cyclic identifying relationships, including super-sub relationships Example 1: Entity A is the parent of B which is the parent of C which is the parent of A. Example 2: An occurrence of entity A is the parent of another occurrence of entity A
•A subentity cannot be the child of an identifying relationship.
•A subentity cannot have more than one supertype.
These tests are only applied to the current diagram; therefore, there might be conflicting relations in the model due to relations between entities on different subject area diagrams. You will be prompted when creating or refreshing a diagram if conflicts exist.