Database Reference
In-Depth Information
8. What is a data dictionary? Describe its purpose.
9. Briefly describe the features of a network data model. How are relationships
represented in a network data model?
10. Is the relational data model better than the earlier data models? Give your
reasons.
EXERCISES
1. Match the columns:
1. data redundancy A. foreign keys for relationships
2. inconsistent data B. data storage
3. data independence C. large data volumes
4. data integration D. used for storing data
5. data repository E. structure definitions
6. data dictionary F. easy to administer
7. decision-support database G. wasted storage space
8. relational data model H. unified view of corporate data
9. centralized database I. data separated from program logic
10. punched card J. errors on customer documents
2. “Escalating demand for information and explosive growth of computing tech-
nology together enabled the evolution of database systems.” Discuss this state-
ment, giving your reasons for agreeing or disagreeing.
3. You are hired as the project leader for a new database project at a local bank.
The bank wants to convert the existing file-oriented systems to a database
system. Your department head wants you to write a note to the Executive Vice
President listing the expected benefits of the proposed database system in
comparison with file-oriented systems. Write a one-page note.
4. Compare the features of the hierarchical, network, and relational data models.
Explain how related data elements are linked in each model.
5. A manufacturer of electronic components has two factories in two different
states. The company has a central warehouse at a location where the head
office is situated. There are five sales offices in five different regions of the
country. Discuss whether the company should have a centralized database
or distributed databases. List the advantages and disadvantages of each
approach.
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