Database-Management-System
August 29, 2024Normalization
August 29, 2024Database-Management-System
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Question 599
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Identify the minimal key for relational scheme R(A, B, C, D, E) with functional dependencies F = {A → B, B → C, AC → D}
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A
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AE
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BE
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CE
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Question 599 Explanation:
Given functional dependencies are F={A → B, B → C, AC → D}
Step-1: Attribute A and E are not present in the right hand side of any production. So, every key should include AE to be a candidate key.
Step-2: To check whether AE could be a candidate key or not.
(AE) + = {A,B,C,D,E}
Since AE can uniquely identify each attribute and we can say this is the candidate key for given relation.
Step-1: Attribute A and E are not present in the right hand side of any production. So, every key should include AE to be a candidate key.
Step-2: To check whether AE could be a candidate key or not.
(AE) + = {A,B,C,D,E}
Since AE can uniquely identify each attribute and we can say this is the candidate key for given relation.
Correct Answer: B
Question 599 Explanation:
Given functional dependencies are F={A → B, B → C, AC → D}
Step-1: Attribute A and E are not present in the right hand side of any production. So, every key should include AE to be a candidate key.
Step-2: To check whether AE could be a candidate key or not.
(AE) + = {A,B,C,D,E}
Since AE can uniquely identify each attribute and we can say this is the candidate key for given relation.
Step-1: Attribute A and E are not present in the right hand side of any production. So, every key should include AE to be a candidate key.
Step-2: To check whether AE could be a candidate key or not.
(AE) + = {A,B,C,D,E}
Since AE can uniquely identify each attribute and we can say this is the candidate key for given relation.