Phillip Morgan, the owner of Morgan Importing, makes periodic buying trips to various countries. During the trips, he keeps notes about the items he purchases and basic data about their shipments. He hired a college student as an intern, and she transformed his notes into the spreadsheets in Figure 4-9. This is just sample data. Phillip has purchased hundreds of items over the years, and they have been shipped in dozens of different shipments.
Phillip wants to enter the information age, thus he has decided to develop a database of his inventory. He wants to keep track of the items he has purchased, their shipments, and eventually customers and sales. To get started, he has asked you to create a database for the data in Figure 4-9.
A. Follow the procedure shown in Figure 4-1 to assess these data.
1. List all functional dependencies.
2. List any multivalued dependencies.
3. List all candidate keys.
4. List all primary keys
5. List all foreign keys.
6. State any assumptions you make as you list these components.
B. List questions you would ask Phillip to verify your assumptions.
C. If there are any multivalued dependencies, create the tables needed to eliminate these dependencies.
D. The relationship between shipment and item data could possibly be inferred by matching values in the From cells to values in the City cells. Describe two problems with that strategy.
E. Describe a change to this spreadsheet that does express the shipment-item relationship.
F. Assume that Phillip wishes to create an updatable database from these data. Design tables you think are appropriate. State all referential integrity constraints.
G. Assume that Phillip wishes to create a read-only database from these data. Design tables you think are appropriate. State all referential integrity constraints.
H. Do these data have the multivalue, multicolumn problem? If so, how will you deal with it?
I. Do these data have the inconsistent data problem? If so, how will you deal with it?
J. Do these data have a null value data problem? If so, how will you deal with it?
K. Do these data have the general-purpose remarks problem? If so, how will you deal with it?