data-mining
August 29, 2024UGC NET CS 2018-DEC Paper-2
August 29, 2024Database-Management-System
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Question 594
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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 ?
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 594 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 594 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).