DBMS made easy test series - bcnf decomposition

Question

$(A)1$ $(B)2$   $(C)4\\$ $(D)\ 5$

Comments

if multivalued attributes cannot be NULL, only 2:

R1(Sid, Email, Dob, Sname) {Sid, Email → DoB, Sname }
R2(Game Likes, Phone No, Course Id, Sid, Email)

However, if attributes can be NULL, 4 :


R1(Sid, Email, Dob, Sname) {Sid, Email → DoB, Sname }
R2(Game Likes, Sid, Email)

R3(Phone No, Sid, Email)

R4(Course Id, Sid, Email)

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your first case : 2 tables sufficient,

is those tables are in BCNF ?

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Shaik Masthan I might be missing something, can you please explain why they are not?

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Listout the FD’s from table, R2(Game Likes, Phone No, Course Id, Sid, Email), then check are those in BCNF or not

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Shaik Masthan got it!!! very silly mistake, thought all of those attributes can work as a composite key.

Answer 1

Answer should be- 4

3 for all different multi valued attribute and one for simple attribute.