Functional-Dependency
August 21, 2024Database-Management-System
August 21, 2024Database-Management-System
| Question 45 |
Consider the following implications relating to functional and multivalued dependencies given below, which may or may not be correct.
(i) If A ↠ B and A ↠ C then A → BC
(ii) If A → B and A → C then A ↠ BC
(iii) If A ↠ BC and A → B then A → C
(iv) If A → BC and A → B then A ↠ C
Exactly how many of the above implications are valid?
| 0 | |
| 1 | |
| 2 | |
| 3 |
Question 45 Explanation:
The rule is
if A→B then A→→B holds but reverse is not true.
So,
(i) False.
(ii) True.
(iii) False.
(iv) True.
if A→B then A→→B holds but reverse is not true.
So,
(i) False.
(ii) True.
(iii) False.
(iv) True.
Correct Answer: C
Question 45 Explanation:
The rule is
if A→B then A→→B holds but reverse is not true.
So,
(i) False.
(ii) True.
(iii) False.
(iv) True.
if A→B then A→→B holds but reverse is not true.
So,
(i) False.
(ii) True.
(iii) False.
(iv) True.