In a relational database, which one of the following is CORRECT:

1. AA relation with only two attributes is always in BCNF.
2. BIf all attributes of a relation are prime attributes then the relation in BCNF
3. CEvery relation has at least one non-prime attribute.
4. DBCNF decomposition preserves functional dependencies.

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

Show answer & explanation

Correct answer: A. A relation with only two attributes is always in BCNF.

Explanation

With two attributes, any non-trivial FD A → B makes A a key, so every two-attribute relation is in BCNF. An all-prime relation is guaranteed only 3NF, a relation can have no non-prime attribute, and BCNF decomposition may lose dependencies.