Which of the following is not a super key in a relational schema with…
2022
Which of the following is not a super key in a relational schema with attributes V, W, X, Y, Z and primary key = VY?
- A.
VXYZ
- B.
VWXZ
- C.
VWXY
- D.
VWXYZ
Attempted by 2011 students.
Show answer & explanation
Correct answer: B
the Primary Key is "VY". This means to uniquely identify any row, you must have both V and Y present in your attribute set.
Option | Attributes Provided | Does it contain V and Y? | Verdict |
A | V, X, Y, Z | Yes (Both V and Y are present) | It is a Super Key |
B | V, W, X, Z | No (Y is missing) | NOT a Super Key |
C | V, W, X, Y | Yes (Both V and Y are present) | It is a Super Key |
D | V, W, X, Y, Z | Yes (Both V and Y are present) | It is a Super Key |