Which of the following statements is NOT true with respect to database…
2013
Which of the following statements is NOT true with respect to database normalization?
- A.
A 4NF table is more immune against logical inconsistencies than a 3NF table.
- B.
A 3NF table will have fewer anomalies than a 2NF table.
- C.
A 3NF table is more vulnerable than a 2NF table.
- D.
A database is said to be in 3NF if all its tables are in 3NF.
Attempted by 634 students.
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Correct answer: C
Correct identification of the NOT true statement:
The statement "A 3NF table is more vulnerable than a 2NF table." is NOT true.
Why this is false:
3NF reduces redundancy beyond 2NF by eliminating transitive dependencies. This reduces insertion, update, and deletion anomalies, so a table in 3NF is generally less vulnerable than the same table left in 2NF.
Short notes on the other statements:
The statement that a 4NF table is more immune against logical inconsistencies than a 3NF table is generally correct: 4NF addresses multi-valued dependencies that 3NF does not, preventing additional redundancy-related issues.
The statement that a 3NF table will have fewer anomalies than a 2NF table is correct because 3NF removes transitive dependencies that cause anomalies.
The statement that a database is in 3NF if all its tables are in 3NF is correct: the database-level normal form is determined by all constituent tables meeting the normal form.