Homework # 9

Distributed Databases & Client-Server

Due: 4/24/2001


Information Resources Management


50 points

Use the information about the Carnegie Library System provided for homework #8.

Additionally, the focus will only be on two major areas:

1. Patron searches for book. A variety of search options are available. However, there are two types of searches. The default will be to search using specified criteria for books only at the current branch. A second option is to search other selected branches or all branches for books meeting the same criteria.

2. Librarians check out books to patrons. A patron can check out a book from any branch provided no fines are due. The librarians also enter when books have been returned. It's possible for someone to return a book that belongs in a different branch. In that case, the librarian still enters that the book has been returned and then puts the book aside for delivery to the proper branch.

The central location and site of the current centralized database is the branch in Oakland. The remaining 18 branches are scattered throughout the Pittsburgh area.

1. Describe how you would implement a client-server system for the Library System. Show what functionality would remain on the server(s) and what functionality would be executed on each of the two types of clients (patron search PC, checkout desk PC). A multi-tiered approach may be recommended. Document any assumptions that you may make about the distribution of the data. (10 points)

2. Describe how you would distribute the database using the following options (20 points)

A. Fragmentation only

B. Replication only

C. Both fragmentation and replication

3. Using the "both fragmentation and replication distribution" option, describe the processing strategy to be used for each of the following transactions. (10 points)

A. Patron searches for a book in the current branch

B. Patron searches for a book at one or two other branches

C. Patron searches for a book at all other branches

D. Librarian checks out a book to a patron

E. Librarian enters the return of a book for the current branch

F. Librarian enters the return of a book for a different branch

4. Recommend one of the distribution options. Provide support for your recommendation, and explain the benefits and drawbacks of the option you selected.