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Which of the following statements is/are FALSE? (i) By definition a relation schema is in first normal form. (ii) A relation schema which is in third normal form is definitely in BCNF.

Which of the following statements is/are FALSE? (i) By definition a relation schema is in first normal form. (ii) A relation schema which is in third normal form is definitely in BCNF. Correct Answer Only (ii)

The correct answer is option 3.

Concept:

Statement 1:  By definition, a relation schema is in first normal form.

True, A relation is in first normal form (abbreviated INF) if the domains of all its attributes are atomic, and the value of any attribute in a tuple is a single value from its domain. An equivalent definition is that each attribute is non-decomposable and is functionally dependent on the key. A relation schema is in first normal form always.

Statement 2: A relation schema that is in third normal form is definitely in BCNF.

False, A table to satisfy the Boyce-Codd Normal Form should satisfy the following two conditions:

  • It should be in the Third Normal Form.
  • And, for any dependency A → B, A should be a super key.

A relation schema that is in the third normal form then that table may or may not in BCNF.

Hence the correct answer is Only (ii).

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