Programming
October 10, 2023Database-Management-System
October 10, 2023Database-Management-System
| Question 40 |
Consider the schema R = (S T U V) and the dependencies S → T, T → U, U → V and V → S. Let R = (R1 and R2) be a decomposition such that R1 ∩ R2 ≠ ∅ . The decomposition is
| not in 2NF | |
| in 2NF but not 3NF | |
| in 3NF but not in 2NF | |
| in both 2NF and 3NF |
Question 40 Explanation:
Since R1 ∩ R2 ≠ ∅, so the decomposition is lossless join. Now since all the attributes are keys, so R1 ∩ R2 will be a key of the decomposed relation.
And since every attribute is key so the decomposed relation will be in BCNF and hence in 3NF.
And since every attribute is key so the decomposed relation will be in BCNF and hence in 3NF.
Correct Answer: D
Question 40 Explanation:
Since R1 ∩ R2 ≠ ∅, so the decomposition is lossless join. Now since all the attributes are keys, so R1 ∩ R2 will be a key of the decomposed relation.
And since every attribute is key so the decomposed relation will be in BCNF and hence in 3NF.
And since every attribute is key so the decomposed relation will be in BCNF and hence in 3NF.
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