Description
COMP353/1 Assignment #3
Exercise #1 (10 points)
Here are the two sets of FDs for R {A, B, C, D, E}.
S = {A->B AB->C D->AC D->E} T = {A->BC D->AE}
Are they equivalent?
Exercise #2 (10 points)
Consider the following decomposition of the table ENROLLMENT in two tables Student and Course.
Table ENROLLMENT
StudentID StudentName CourseName Credits
1111111 William Smith COMP218 4
2222222 Michel Cyr COMP353 4
3333333 Charles Fisher COMP348 4
4444444 Patricia Roubaix COMP353 4
2222222 Paul Paul COMP352 3
5555555 Lucie Trembaly COMP354 3
Table Student
StudentID StudentName Credits
1111111 William Smith 4
2222222 Michel Cyr 4
3333333 Charles Latan 4
4444444 Patricia Roubaix 4
2222222 Paul Paul 3
5555555 Lucie Trembaly 3
Table Course
Credits CourseName
4 COMP218
4 COMP353
4 COMP348
4 COMP353
3 COMP352
3 COMP354
Question: Is this decomposition lossless? Justify.
Exercise #3 (15 points)
Using the Functional Dependencies,
F = {A → BC ; CD → E ; B→D ; E→A}
a) Compute the closure of F (F+).
b) Is true / false : F ⊨ E → BC?
c) Provide the minimal cover Fc (min(F)) using steps shown in the class.
d) List of the candidate keys for R
Exercise #4 (15 points)
Consider the relation R(S, N, R, C, J, H, L) and the set of dependencies.
F = {S, N C ; J, H, C L ; J, H, L S, N, R ; S, N, R J, H, L}.
Prove that F ⊨ J, H, S, N R using the Armstrong’s axioms?
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