August 2009
Intermediate to advanced
893 pages
26h 48m
English
Content preview from Database Systems: Concepts, Design and Applications
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
State True/False
| 1. | Subclasses are the sub-grouping of occurrences of entities in an entity type that shares common attributes or relationships distinct from other sub-groupings. |
| 2. | In case of supertype, objects in one set are grouped or subdivided into one or more classes in many systems. |
| 3. | Superclass is a generic entity type that has a relationship with one or more subtypes. |
| 4. | Each member of the subclass is also a member of the superclass. |
| 5. | The relationship between a superclass and a subclasses is a one-to-many (1:N) relationship. |
| 6. | The U-shaped symbols in ERR model indicates that the supertype is a subset of the subtype. |
| 7. | Attribute inheritance is the property by which supertype entities inherit values of all attributes of the subtype. |
| 8. ... |