GATE CS 2024 Set 1 | Question 22

MSQ · 1 mark

Which of the following statements about a relation R in first normal form (1NF) is/are TRUE ?

  1. Option A: R can have a multi-attribute key (correct)
  2. Option B: R cannot have a foreign key
  3. Option C: R cannot have a composite attribute (correct)
  4. Option D: R cannot have more than one candidate key

Answer

(A), (C)

Explanation

First normal form asks only that every attribute hold atomic (indivisible) values, so a 1NF relation has no composite or multivalued attributes. It says nothing about keys.

  • A: true. A key made of several attributes, such as (RollNo, CourseNo), is allowed; atomicity is about values, not keys.
  • B: false. A relation in any normal form may have a foreign key referring to another relation.
  • C: true. A composite attribute such as Address (street, city, PIN) is not atomic, so in 1NF it must be split into simple attributes.
  • D: false. A relation can have several candidate keys, for example both RollNo and Email in a student table.

Answer: A, C