Question

Choose the false statement about the decomposition into 3NF?

Select one:
a. The decomposition has a lossless join.
b. The decomposition has the dependency preservation property.
c. The decomposition eliminates all anomalies.
d. The relations of the decomposition are all in 3NF.

Answer 1

The false statement about decomposition into 3NF is that it eliminates all anomalies. Decomposition to 3NF aims to reduce redundancy and update anomalies but does not guarantee the elimination of all potential anomalies within a database.

Step-by-step explanation:

The false statement about the decomposition into 3NF (Third Normal Form) is:

c. The decomposition eliminates all anomalies.

While decomposition into 3NF is designed to reduce redundancy and update anomalies by ensuring that every non-prime attribute is non-transitively dependent on every key of the database, not all anomalies are guaranteed to be eliminated. There can still be situations where anomalies occur, particularly when there are compromises between dependency preservation and other constraints. Decomposition into 3NF involves ensuring that all relations are in 3NF, preserving dependencies when breaking down the relations, and that the join of the decomposed relations results in the original relation (a lossless join).

Therefore, while a correct 3NF decomposition will ensure that all relations are in 3NF, has a lossless join, and aims at dependency preservation, it does not guarantee the elimination of all potential anomalies within a database.