Database-Management-System
August 29, 2024Database-Management-System
August 29, 2024Database-Management-System
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Question 388
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A super key for an entity consists of
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one attribute only
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At least two attributes
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at most two attributes
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one or more attributes
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Question 388 Explanation:
Super key is a set of attributes of a relation schema upon which all attributes of the schema are functionally dependent. It can consist of one or more attributes.
For example : Consider a relation R(A,B,C,D) where “A” is the candidate key of “R” then Superkeys of “R” will be {A,AB, AC, AD, ABC, ABD, ACD, ABCD}.
For example : Consider a relation R(A,B,C,D) where “A” is the candidate key of “R” then Superkeys of “R” will be {A,AB, AC, AD, ABC, ABD, ACD, ABCD}.
Correct Answer: D
Question 388 Explanation:
Super key is a set of attributes of a relation schema upon which all attributes of the schema are functionally dependent. It can consist of one or more attributes.
For example : Consider a relation R(A,B,C,D) where “A” is the candidate key of “R” then Superkeys of “R” will be {A,AB, AC, AD, ABC, ABD, ACD, ABCD}.
For example : Consider a relation R(A,B,C,D) where “A” is the candidate key of “R” then Superkeys of “R” will be {A,AB, AC, AD, ABC, ABD, ACD, ABCD}.