Multiple choice

Which of the following statements about normal forms is FALSE?

  1. BCNF is stricter than 3 NF.

  2. Lossless, dependency preserving decomposition into 3 NF is always possible.

  3. Lossless, dependency preserving decomposition into BCNF is always possible.

  4. Any relation with two attributes is BCNF.
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C Correct answer
Explanation

(1) BCNF stricter than 3NF is true. (2) True, dependency preserving lossless decomposition into 3NF is always possible by removing transitive functional dependences. (3) False, lossless dependency preserving decomposition is not possible in all the cases, when all non-  trivial functional dependencies are not dependent upon super keys. (4) Certainly relation with two attributes is in BCNF, both will consist of super key.

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