Database-Management-System
August 29, 2024Database-Management-System
August 29, 2024Database-Management-System
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Question 395
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Consider the relation R shown in the below Figure.
| X | Y | Z |
| X1 | Y1 | Z1 |
| X1 | Y1 | Z2 |
| X2 | Y1 | Z1 |
| X2 | Y1 | Z3 |
List all the functional dependencies that this relation instance satisfies.
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R: Z → Y, X → Y, and X → Z
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R: Z →Y, X → Y, and XZ → Y
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R: X →Y, X → Z, and XZ → Y
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R: Z →Y, X → Z, and XZ → Y
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Question 395 Explanation:
option 1 is wrong bacause X → Z does not satisfy, since X1 is mapped to two values Z1 and Z2.
Option 3 is wrong because of X → Z.
Option 4 is wrong because of X → Z
Option 3 is wrong because of X → Z.
Option 4 is wrong because of X → Z
Correct Answer: B
Question 395 Explanation:
option 1 is wrong bacause X → Z does not satisfy, since X1 is mapped to two values Z1 and Z2.
Option 3 is wrong because of X → Z.
Option 4 is wrong because of X → Z
Option 3 is wrong because of X → Z.
Option 4 is wrong because of X → Z