Question 7942 – Relational-Algebra
May 3, 2024Database-Management-System
May 3, 2024Database-Management-System
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Question 806
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Consider the schema R = (A, B, C, D, E, F) on which the following functional dependencies hold :
A ➝ B B, C ➝ D E ➝ C D ➝ A
What are the candidate keys of R ?
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AEF, BEF and DEF
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AEF, BEF and BCF
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AE and BE
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AE, BE and DE
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Question 806 Explanation:
EFA+ = {EFABCD}
EFB+ = {EFABCD}
EFC+ = {EFC}
EFD+ = {EFDCAB}
So, EFA, EFB, EFD are the keys for the given relation R = (A, B, C, D, E, F).
EFB+ = {EFABCD}
EFC+ = {EFC}
EFD+ = {EFDCAB}
So, EFA, EFB, EFD are the keys for the given relation R = (A, B, C, D, E, F).
Correct Answer: A
Question 806 Explanation:
EFA+ = {EFABCD}
EFB+ = {EFABCD}
EFC+ = {EFC}
EFD+ = {EFDCAB}
So, EFA, EFB, EFD are the keys for the given relation R = (A, B, C, D, E, F).
EFB+ = {EFABCD}
EFC+ = {EFC}
EFD+ = {EFDCAB}
So, EFA, EFB, EFD are the keys for the given relation R = (A, B, C, D, E, F).