Match List I with List II : \(\begin{array}{ll} \text{List I} & \text{List II}…
2022
Match List I with List II :
\(\begin{array}{ll} \text{List I} & \text{List II} \\ \\ \text {(A) BCNF } & \text { (I) It removes multivalued dependency } \\ \text {(B) 3} \mathrm{NF} & \text { (II) It is not always dependency preserving } \\ \text {(C) 2} \mathrm{NF} & \text{ (III) It removes transitive dependency} \\ \text {(D) 4} \mathrm{NF} & \text { (IV) It removes partial functional dependency }\end{array}\)
Choose the correct answer from the options given below:
- A.
(A)-(III), (B)-(II), (C)-(IV), (D)-(I)
- B.
(A)-(II), (B)-(IV), (C)-(I), (D)-(III)
- C.
(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
- D.
(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
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Correct answer: C
Correct matching: the correct associations between the normal forms and their effects are given below.
BCNF → It is not always dependency preserving. BCNF (Boyce–Codd Normal Form) is stricter than 3NF and may require decompositions that do not preserve all original functional dependencies.
3NF → It removes transitive dependency. Third Normal Form eliminates transitive dependencies where a non-key attribute depends on another non-key attribute.
2NF → It removes partial functional dependency. Second Normal Form removes partial dependencies of attributes on part of a composite primary key.
4NF → It removes multivalued dependency. Fourth Normal Form addresses multivalued dependencies, preventing anomalies caused by independent multi-valued facts.
Therefore the correct mapping is: BCNF → not always dependency preserving; 3NF → removes transitive dependency; 2NF → removes partial functional dependency; 4NF → removes multivalued dependency.
Common misconception to avoid: attributing transitive-dependency removal to BCNF or multivalued-dependency removal to 3NF is incorrect. Each normal form targets specific kinds of anomalies as listed above.
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