📝 Question
#1262
R (A,B,C,D) is a relation. Which of the following does not have a lossless join dependency preserving BCNF decomposition?
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Correct Answer
A. A->B, B->CD
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Explanation
This relation gives a relation without any loss in the values. 4. Class (course id, title, dept name, credits, sec id, semester, YEAR, building, room NUMBER, capacity, TIME slot id) The SET OF functional dependencies that we require TO hold ON class are: course id->title, dept name, credits building, room number->capacity course id, sec id, semester, year->building, room NUMBER, TIME slot id A candidate KEY FOR this schema IS {course id, sec id, semester, YEAR} a) Course id-> title, dept name, credits b) Title-> dept name, credits c) Dept name-> credits d) Cannot be determined Here course id is not a superkey. Thus, class is not in BCNF.
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