For a database relation R(a, b, c, d) where the domains of a, b, c and d include only atomic values, and only the following functional dependencies and those that can be inferred from them hold :

a → c

b → d The relation is in _________.

1. AFirst normal form but not in second normal form
2. BSecond normal form but not in third normal form
3. CThird normal form
4. DBCNF

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: A. First normal form but not in second normal form

Explanation

The only key is ab. a → c and b → d are partial dependencies on part of the key, so R is in 1NF but not 2NF.