Discussion
Which of the following is NOT a superkey in a relational schema with attributes \(V, W, X, Y, Z\) and primary key \(VY\)?
Answer: B
The attribute set that is NOT a superkey is \(VWXZ\).
A superkey is any attribute set that contains a candidate key. The primary key is \(VY\), so any set containing both \(V\) and \(Y\) is a superkey.
\(VXYZ\), \(VWXY\) and \(VWXYZ\) all contain \(V\) and \(Y\). \(VWXZ\) is missing \(Y\); with no other candidate key given, it cannot be assumed to identify tuples uniquely, so it is not a superkey.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development