Chapter 7 homework
1. It is easier to organize data and retrieve it when there is little or no dependence between pro- grams and data. Why is there more such depen- dence in a file approach and less in the database approach?
2. Spreadsheets have become quite powerful for data management. What can be done with database management systems that cannot be done with spreadsheet applications? Give several examples.
3. What is the difference between a database and a database management system?
4. DBMSs are usually bundled with powerful pro- gramming language modules. Why?
5. DBMSs are a component of every enterprise application, such as a supply chain manage- ment system. Why?
6. What are the advantages and disadvantages of object-oriented databases?
7. What is the relationship between a Web site’s local search engines and online databases?
8. When constructing a database, the designer must know what types of relationships exist between records in different data sets, such as one-to-many or many-to-many. Give three examples for each of these relationships.
9. Give an example of a one-to-one relationship in a relational database.
10. What is SQL? In which database model does it operate? Why is it so popular?
11. What is a data warehouse? How is it different from a transactional database?
12. Why is it not advisable to query data from transactional databases for executive decision making the same way you do data warehouses?
13. What are the phases of adding data to a data warehouse?
14. What does it mean to cleanse data before it is stored in a data warehouse?
15. What are data marts? How do they differ from data warehouses?
chapter 6 homework
1. If all the paths of data communications were visible to the human eye, we might be overwhelmed. Why? Give some examples.
2. Data communications over long distances is carried out one bit after another. Why can’t whole bytes be transmitted over a distance one byte per signal?
3. What makes one medium capable of greater data communication speed than another?
4. Which medium currently enables the fastest data communications?
5. Repeaters are used on many communication lines. What is their purpose? What does a repeater do?
6. Networking professionals speak of “the last mile.” What is “the last mile,” and what is its significance?
7. Would an astronomy observatory 20 miles away from a city or town likely be able to get DSL service? Why?
8. What risks to organizations does the growing use of networks pose?
9. What is a virtual private network? Why is it called “virtual”?
10. What is a network protocol?
11. What are the technical advantages of optical fibers over other communications media?
12. The same communication medium can trans- port three different services. This is true of two media. Which media? What are the three services?
13. What is the difference between circuit switching and packet switching?
14. Why does circuit switching accommodate voice communication more effectively than packet switching?
15. What is VoIP? Since VoIP uses packet switching, why is voice quality better now than several years ago?
16. What is ADSL? What does the A stand for, and what does it mean in terms of communicating with the Internet? Why do households receive only ADSL services and not other DSL services?
17. What is BPL? Why is the technology potentially available to almost every home?
18. Explain the notions of WAN, LAN, MAN, and PAN.
19. What are hotspots, and how can they help businesspeople?
20. What is the purpose of municipally provided WiMAX, and why is it in competition with subscriber broadband services?
21. Cellular phones are already wireless. Why should companies be interested in equipping employees with Wi-Fi-enabled mobile phones?