6354099
Pregunta 1
Pregunta
1. The entity super type contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.
Respuesta
- True
- False
Pregunta 2
Pregunta
2. Entity super types and subtypes are organized in a specialization hierarchy.
Respuesta
- True
- False
Pregunta 3
Pregunta
3. The relationships depicted within the specialization hierarchy are sometimes described in terms of “is-a” relationships.
Respuesta
- True
- False
Pregunta 4
Pregunta
4. Within a specialization hierarchy, a super type can exist only within the context of a subtype.
Respuesta
- True
- False
Pregunta 5
Pregunta
5. One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their super type.
Respuesta
- True
- False
Pregunta 6
Pregunta
6. At the implementation level, the super type and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship.
Respuesta
- True
- False
Pregunta 7
Pregunta
7. Entity subtypes do not inherit the relationships in which the super type entity participates.
Respuesta
- True
- False
Pregunta 8
Pregunta
8. In specialization hierarchies with multiple levels of super type/subtypes, a lower-level super type inherits all of the attributes and relationships from all of its upper-level subtypes.
Respuesta
- True
- False
Pregunta 9
Pregunta
9. The property of subtype discriminator enables an entity super type to inherit the attributes and relationships of the subtype.
Respuesta
- True
- False
Pregunta 10
Pregunta
10. An entity super type can have disjoint or overlapping entity subtypes
Respuesta
- True
- False
Pregunta 11
Pregunta
11. Disjoint subtypes are subtypes that contain non unique subsets of the super type entity set.
Respuesta
- True
- False
Pregunta 12
Pregunta
12. Overlapping subtypes are subtypes that contain a unique subset of the super type entity set
Respuesta
- True
- False
Pregunta 13
Pregunta
13. Implementing non-overlapping subtypes requires the use of one discriminator attribute for each subtype.
Respuesta
- True
- False
Pregunta 14
Pregunta
14. The completeness constraint can be partial or total.
Respuesta
- True
- False
Pregunta 15
Pregunta
15. Specialization is the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity super type.
Respuesta
- True
- False
Pregunta 16
Pregunta
16. Generalization is based on grouping unique characteristics and relationships of the subtypes.
Respuesta
- True
- False
Pregunta 17
Pregunta
17. An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.
Respuesta
- True
- False
Pregunta 18
Pregunta
18. To model time-variant data, you must create a new entity in a M:N relationship with the original entity.
Respuesta
- True
- False
Pregunta 19
Pregunta
19. A design trap occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world.
Respuesta
- True
- False
Pregunta 20
Pregunta
20. Some designs use redundant relationships as a way to simplify the design.
Respuesta
- True
- False
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