Nielit Scentist-B [02-12-2018]
October 10, 2023Nielit Scentist-B [02-12-2018]
October 10, 2023Database-Management-System
| Question 815 |
Maximum number of superkeys for the relation schema R(X,Y,Z,W) with X as the key is:
| 6 | |
| 8 | |
| 9 | |
| 12 |
Question 815 Explanation:
→ Maximum no. of possible super keys for a relation with n attributes with one candidate key
(only one attribute) = 2n-1
Here, n = 4.
→ So, the possible super keys = 24-1 = 8
→ The super keys are: X, XY, XZ, YZ, XYZ, XYW, YZW, XYZW.
(only one attribute) = 2n-1
Here, n = 4.
→ So, the possible super keys = 24-1 = 8
→ The super keys are: X, XY, XZ, YZ, XYZ, XYW, YZW, XYZW.
Correct Answer: B
Question 815 Explanation:
→ Maximum no. of possible super keys for a relation with n attributes with one candidate key
(only one attribute) = 2n-1
Here, n = 4.
→ So, the possible super keys = 24-1 = 8
→ The super keys are: X, XY, XZ, YZ, XYZ, XYW, YZW, XYZW.
(only one attribute) = 2n-1
Here, n = 4.
→ So, the possible super keys = 24-1 = 8
→ The super keys are: X, XY, XZ, YZ, XYZ, XYW, YZW, XYZW.
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