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4 Answers

4 votes
4 votes

BCNF is lossless but dependency preservation isn't guaranteed.

So it may or mayn't be dependency preserving.

A,B,C. Not always true. 

So D is correct. 

Ref: https://www.iitg.ac.in/awekar/teaching/cs344fall11/lecturenotes/september%2006.pdf

2 votes
2 votes
This is a tricky quesion .
The question says that “EVERY BCNF ”
As we know not all BCNF will be dependency preserving
Therefore the answer is option B
1 votes
1 votes
UNF--->1NF (Eliminate  multivalue in a cloumn)

1NF-->2NF  Eliminate partial dependency

2NF--> 3NF  Eliminate transitive dependency

3NF-->BCNF  All Determinants must be Candiddate key

Hence BCNF may be Dependency preserving and it is not sure. Hence the option D is correct.
1 votes
1 votes
BCNF decomposition is not always dependency preserving hence ans is D
Answer:

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