Which one of the following pairs is correctly matched in the context of…
2016
Which one of the following pairs is correctly matched in the context of database design ?
\(\begin{array}{|l|l|l|l|}\hline & \text{List-I(Database term)} && \text{List-II(Definition)} \\\hline \text{I.} & \text{Specialization} & \text{A.} & \text{ Result of taking the union of two or more} \\ &&&\text{disjoint (lower-level) entity sets to produce} \\&&&\text{a higher-level entity set.} \\\hline \text{II.} & \text{Generalization} & \text{B.} & \text{Express the number of entities to which} \\ &&& \text{another entity can be associated via a} \\ &&& \text{relationship set.} \\\hline \text{III.} & \text{Aggregation} & \text{C.} & \text{Result of taking a subset of a higher-level} \\ &&& \text{entity set to form a lower-level entity set.} \\\hline \text{IV.} & \text{Mapping cardinality} & \text{D.} & \text{An abstraction in which relationship sets} \\&&& \text{(along with their associated entity sets) are} \\ &&& \text{treated as higher-level entity sets, and can} \\ &&& \text{participate in relationships. } \\\hline \end{array}\)
Codes :
- A.
I-D, II-A, III-B, IV-C
- B.
I-D, II-C, III-B, IV-A
- C.
I-C, II-D, III-A, IV-B
- D.
I-C, II-A, III-D, IV-B
Attempted by 179 students.
Show answer & explanation
Correct answer: D
Explanation: match each database term to its correct definition and why it fits.
Specialization: Result of taking a subset of a higher-level entity set to form a lower-level entity set.
Generalization: Result of taking the union of two or more disjoint lower-level entity sets to produce a higher-level entity set.
Aggregation: An abstraction in which relationship sets (along with their associated entity sets) are treated as higher-level entity sets, and can participate in relationships.
Mapping cardinality: Expresses the number of entities to which another entity can be associated via a relationship set.
Conclusion: The correct pairings are Specialization → the subset definition, Generalization → the union-of-disjoint-lower-level-entity-sets definition, Aggregation → the abstraction treating relationship sets as higher-level entity sets, and Mapping cardinality → the definition expressing how many entities can be associated via a relationship. The choice that lists these pairings in that order is the correct answer.