Exam-style question
Try this first
Which statement describes a relation in third normal form (3NF)?.
- A.It contains no duplicate rows, but attributes may depend on other non-key attributes.
- B.It is in second normal form and no non-key attribute depends on another non-key attribute.
- C.Every attribute in the relation must be part of the primary key.
- D.The relation must contain at least three tables.
Model answer
What a good answer should say
- It is in second normal form and no non-key attribute depends on another non-key attribute.
Explanation
Why this works
A relation in 3NF must already be in second normal form and must not contain transitive dependencies, where a non-key attribute depends on another non-key attribute rather than directly on the key.
Common mistake
No common mistake is linked to this question yet.