Is the answer option 3?

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PLEASE SOMEONE EXPLAIN ME THAT WHY 2ND OPTION IS TRUE ? I AM NOT GETTING THIS OPTION HELP ME

R(A,B,C,D) is a relation. Which of the following does not have a lossless join, dependency preserving BCNF decomposition?

- A→B,B→CD
- A→B,B→C,C→D
- AB→C,C→AD
- A→BCD

+1

The BCNF decompostion of option 2 will be R1(A,B), R2(B,C) and R3(C,D).

We can see that these three relations are lossless (by drawing table).For dependency preserving, from R1 er get the fd A->B, from R2 we get B->C and from R3 we get C->D.Thus we can obtain all the FDs and hence the relation is dependency preserving

We can see that these three relations are lossless (by drawing table).For dependency preserving, from R1 er get the fd A->B, from R2 we get B->C and from R3 we get C->D.Thus we can obtain all the FDs and hence the relation is dependency preserving

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