GATE CSE 2024 | Set 1 | Question: 12

Question

Which of the following statements about a relation $\mathbf{R}$ in first normal form $\text{(1NF)}$ is/are TRUE?

• A. $\mathbf{R}$ can have a multi-attribute key
• B. $\mathbf{R}$ cannot have a foreign key
• C. $\mathbf{R}$ cannot have a composite attribute
• D. $\mathbf{R}$ cannot have more than one candidate key

Answer 1

B ,D are straightforward false because we can have a foreign key in 1NF and also we can have more than one candidate key.

The correct answer is A and C.

Source: Navathe

Source: Korth

Comments

Yes this should be correct answer

Answer 2

Option A

R can have a multi-attribute key

C is correct

Relation not in 1NF if it has composite or multivalued attributes. (Thanks for correction @Philosophical_Virus)

D and B are ofcourse trivially wrong, take an example of any where we decompose any relation using 3NF decomposition, not after decomposition if it is in 3NF then for sure it will be in 1NF, having foreign key and more than one candidate key.

Comments

I found this on GFG please check once for option C

link: https://www.geeksforgeeks.org/first-normal-form-1nf/