Project ForgeCommon Data for this question (continued): Relation R has eight attributes ABCDEFGH, with F = {CH→G, A→BC, B→CFH, E→A, F→EG} as its full set of functional dependencies, and candidate keys AD, BD, ED, FD (as found in the previous question).
The relation R is
- in 1NF, but not in 2NF.
- Bin 2NF, but not in 3NF.
- Cin 3NF, but not in BCNF.
- Din BCNF.
Explanation
The prime attributes (those appearing in some candidate key) are A, B, D, E, F; the non-prime attributes are C, G, H. The FD A→BC has A as a PROPER SUBSET of the candidate key AD (not the whole key), and it determines C, a non-prime attribute — this is a textbook partial dependency, which directly violates 2NF (2NF requires every non-prime attribute to depend on the WHOLE of every candidate key, not just part of it). Since R still satisfies 1NF (all attributes are atomic), R is in 1NF but not 2NF.
Source: GATE CS 2013 (2013)
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