A table has fields Fl, F2, F3, F4, F5 with the following functional…
2005
A table has fields Fl, F2, F3, F4, F5 with the following functional dependencies
F1 → F3 F2→ F4 (F1 . F2) → F5
In terms of Normalization, this table is in
- A.
1 NF
- B.
2 NF
- C.
3 NF
- D.
none
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Show answer & explanation
Correct answer: A
Answer: 1 NF
Explanation:
Determine the candidate key: The functional dependencies F1 → F3, F2 → F4, and (F1, F2) → F5 imply that {F1, F2} determines all attributes (F3, F4, F5), so {F1, F2} is a candidate key.
Check First Normal Form (1NF): Assuming attributes are atomic, the relation is in 1NF.
Check Second Normal Form (2NF): Because the key is composite, 2NF requires that no non-prime attribute depend on part of the key. However, F1 → F3 and F2 → F4 are partial dependencies (non-prime attributes F3 and F4 depend on parts of the composite key), so 2NF is violated.
Conclusion: The relation is in 1NF but not in 2NF (and therefore not in 3NF).