Description
Exercise #1
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
a) Compute the closure of the following set F of functional dependencies for relation schema R =
{A, B, C, D, E}.
F = {A → BC ; CD → E ; B→D ; E→A}
b) List the candidate keys for R.
Exercise #3
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 Table Course
StudentID StudentName Credits Credits CourseName
1111111 William Smith 4 4 COMP218
2222222 Michel Cyr 4 4 COMP353
3333333 Charles Latan 4 4 COMP348
4444444 Patricia Roubaix 4 4 COMP353
2222222 Paul Paul 3 3 COMP352
5555555 Lucie Trembaly 3 3 COMP354
Question: Is this decomposition lossless? Justify.
Exercise #4
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)).
d) List of the candidate keys for R
Submitting Assignment #2
– Naming convention file: Create one file .pdf, containing your solution of your assignment
using the following naming convention:
The pdf file should be called A2_TeamName, where TeamName is your student
group name.
– Submit your pdf file in the appropriate assignment folder via ENCS Website. The deadline is
not respected would be discarded and no replacement submission will be allowed.
– Submit only ONE version of an assignment for each team. It is not an individual submission. If
more than one version is submitted the last one, before the deadline date, will be graded and all
others will be disregarded.
Evaluation Criteria of Assignment #2 (50 points)
Activities Points
Exercise #1:
– Are S and T equivalent? 10 pts.
10 pts.
Exercise #2:
– Compute the closure of the following set F of functional
dependencies for relation schema R. 5 pts.
– List the candidate keys for R. 5 pts.
10 pts.
Exercise #3:
– Is this decomposition lossless? Justify. 5 pts.
5 pts.
Exercise #4:
– Compute the closure of F (F+
). 5 pts.
– Is true / false : F ⊨ → E → BC?. 5 pts.
– Provide the minimal cover Fc
(min(F)). 10 pts.
– List of the candidate keys for R. 5 pts.
25 pts.
