Project ForgeDatabase Management Systems
Normalization
GATE 2012
Medium
Which of the following is TRUE?
- AEvery relation in 3NF is also in BCNF
- BA relation R is in 3NF if every non-prime attribute of R is fully functionally dependent on every key of R
- Every relation in BCNF is also in 3NF
- DNo relation can be in both BCNF and 3NF
Explanation
BCNF is a strictly stronger condition than 3NF (BCNF requires every determinant of a functional dependency to be a superkey, stricter than 3NF's exception for prime attributes). So every relation satisfying BCNF automatically satisfies 3NF — making (C) true and (A) false. (D) is false since many relations are trivially in both.
Source: GATE CS 2012 (2012)
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