Quiz
Chapter 5 (True/False)
Questions in this quiz (20)
11. The entity super type contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.
- ATrue
- BFalse
22. Entity super types and subtypes are organized in a specialization hierarchy.
- ATrue
- BFalse
33. The relationships depicted within the specialization hierarchy are sometimes described in terms of “is-a” relationships.
- ATrue
- BFalse
44. Within a specialization hierarchy, a super type can exist only within the context of a subtype.
- ATrue
- BFalse
55. One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their super type.
- ATrue
- BFalse
66. At the implementation level, the super type and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship.
- ATrue
- BFalse
77. Entity subtypes do not inherit the relationships in which the super type entity participates.
- ATrue
- BFalse
88. 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.
- ATrue
- BFalse
99. The property of subtype discriminator enables an entity super type to inherit the attributes and relationships of the subtype.
- ATrue
- BFalse
1010. An entity super type can have disjoint or overlapping entity subtypes
- ATrue
- BFalse
1111. Disjoint subtypes are subtypes that contain non unique subsets of the super type entity set.
- ATrue
- BFalse
1212. Overlapping subtypes are subtypes that contain a unique subset of the super type entity set
- ATrue
- BFalse
1313. Implementing non-overlapping subtypes requires the use of one discriminator attribute for each subtype.
- ATrue
- BFalse
1414. The completeness constraint can be partial or total.
- ATrue
- BFalse
1515. Specialization is the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity super type.
- ATrue
- BFalse
1616. Generalization is based on grouping unique characteristics and relationships of the subtypes.
- ATrue
- BFalse
1717. An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.
- ATrue
- BFalse
1818. To model time-variant data, you must create a new entity in a M:N relationship with the original entity.
- ATrue
- BFalse
1919. 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.
- ATrue
- BFalse
2020. Some designs use redundant relationships as a way to simplify the design.
- ATrue
- BFalse
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- asdf Quiz on Chapter 5 (True/False), created by . . on 15/09/2016.
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- . .
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- Created on 15 Sep 2016 · updated on 13 Oct 2016
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