Database-Management-System
August 29, 2024Database-Management-System
August 29, 2024Database-Management-System
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Question 726
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Given an instance of the relation R(ABCD).
Which of the following functional dependencies hold?
Which of the following functional dependencies hold?
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{AB} → D and D → A
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{AB → D and B → D
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{AB} → C and B → C
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{AB} → D and A → D
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Question 726 Explanation:
Rules for determining functional dependency hold or not :
→ If LHS of a functional dependency is not repeating any value then you. you can say that LHS of a functional dependency is determining RHS of a functional dependency.
→ If LHS of a functional dependency is repeating then see the value of RHS. If values of RHS are same for repeated value of LHS then you can say that LHS of a functional dependency is determining RHS of a functional dependency else not determining.
Now if you see the given options then only option(C) is satisfying above two rules.
→ If LHS of a functional dependency is not repeating any value then you. you can say that LHS of a functional dependency is determining RHS of a functional dependency.
→ If LHS of a functional dependency is repeating then see the value of RHS. If values of RHS are same for repeated value of LHS then you can say that LHS of a functional dependency is determining RHS of a functional dependency else not determining.
Now if you see the given options then only option(C) is satisfying above two rules.
Correct Answer: C
Question 726 Explanation:
Rules for determining functional dependency hold or not :
→ If LHS of a functional dependency is not repeating any value then you. you can say that LHS of a functional dependency is determining RHS of a functional dependency.
→ If LHS of a functional dependency is repeating then see the value of RHS. If values of RHS are same for repeated value of LHS then you can say that LHS of a functional dependency is determining RHS of a functional dependency else not determining.
Now if you see the given options then only option(C) is satisfying above two rules.
→ If LHS of a functional dependency is not repeating any value then you. you can say that LHS of a functional dependency is determining RHS of a functional dependency.
→ If LHS of a functional dependency is repeating then see the value of RHS. If values of RHS are same for repeated value of LHS then you can say that LHS of a functional dependency is determining RHS of a functional dependency else not determining.
Now if you see the given options then only option(C) is satisfying above two rules.