Last modified on 16 June 2009, at 19:21

# Data Management in Bioinformatics/Exercise 1

Figures are here: http://pipe.cs.vt.edu/~pbutler/bi_and_db/ until I can upload them (takes 4 days to get confirmed for media upload).

1. File:Problem1.svg
Notes: 1) For each reservation, 1 <= # of drivers <= 10

2. Notes:
• A book seller must have at least one store.
• A book store must be either web-based or brick, but not both.
3. Maximum: n is the case where all n are one-to-one. Minimum: n-1 is the case where n-1 one-to-many
4. File:Problem4.svg
5. File:Problem5.svg
6. FD Trivial
$A \rightarrow B$ YES
$B \rightarrow A$ NO
$A \rightarrow C$ NO
$C \rightarrow A$ NO
$B \rightarrow C$ NO
$C \rightarrow B$ YES
MD Trivial
$A \rightarrow \rightarrow B | A \rightarrow \rightarrow C$ YES
$B \rightarrow \rightarrow A | B \rightarrow \rightarrow C$ NO
$C\rightarrow \rightarrow A | C \rightarrow \rightarrow B$ YES
7. Obvious
8. $R(A,B,C,D,E,G)$ decomposes into $R_1(A,B,C)$, $R_2(A,C,D,E)$, $R_3(A,D,G)$
The FDs $B \rightarrow D$, $E \rightarrow G$ are not preserved.
$R_1$ and $R_2$ are decomposed losslessly because $A C \rightarrow B$
$R_2$ and $R_3$ are decomposed losslessly because $A D \rightarrow E$ and $E \rightarrow G$ translates into $A D \rightarrow G$
9. #6 redone
10. There are several solutions to this:
LHS RHS
$B \cap C \rightarrow$ $A - C$ $B - C$ $B$ (superset)
$B \cap C \rightarrow$ $A - B$ $C - B$ $C$ (superset)