ELEC 4/6273 Database Engineering
Homework # 13
1. Given: R( A, B, C, D, E, F, G, H, I, J )
F = { AB ® C, A ® DE, B ® F, F ® GH, D ® IJ }
Determine whether each decomposition has the lossless join property with respect to F.
a) R1( A, B, C)
R2( A, D, E)
R3( B, F )
R4( F, G, H )
R5( D, I, J )
R2( B, F,G, H )
R3( D, I, J )
R2( D, E )
R3( B, F)
R4( F, G, H)
R5( D, I, J )
2. Given R(A,B,C) with the data as shown in the table that follows:
R: A B C
w x p
w x q
z x p
z x q
w y q
z y p
Explain and/or demonstrate your answer to the following questions (a simple yes or no will not suffice).
a) Does the multi-valued dependency (MVD) B->>C hold? Explain.
b) Can R be lossless 2-decomposed? Explain.
c) Can R be lossless 3-decomposed? Explain.
d) Is R in 4NF? Explain.
e) Is R in 5NF? Explain.