Constraints
January 9, 2024Database-Management-System
January 9, 2024Constraints
| Question 1 |
Which of the following statements about “total specialization” constraint is TRUE?
| Every entity in the subclass must be a member of the superclass. | |
| Every entity in the superclass must be a member of at least one subclass in the specialization. | |
| At least one entity in the superclass must be a member of at least one subclass in the specialization. | |
| Every entity in the superclass must be a member of all subclass in the specialization. |
Question 1 Explanation:
→The total specialization rule demands that every entity in the superclass belong to some subclass.
→The partial specialization rule allows an entity to not belong to any of the subclasses
→The partial specialization rule allows an entity to not belong to any of the subclasses
Correct Answer: B
Question 1 Explanation:
→The total specialization rule demands that every entity in the superclass belong to some subclass.
→The partial specialization rule allows an entity to not belong to any of the subclasses
→The partial specialization rule allows an entity to not belong to any of the subclasses