Topic 1 Database Systems Tutorial Questions for Week 2-3 1. Discuss each of the following terms: a data b. field C. record d. file 2. What is data redundancy, and which characteristics of the file system can lead to it? 3. What is data independence, and why is it lacking in file systems? 4. What is a DBMS, and what are its functions? 5. What is structual independence, and why is it important? 6. Explain the difference between data and information. 7. What is the role of a DBMS, and what are its advantages? What are its disadvantages? 8. List and describe the different types of databases. 9. What are the main components of a database system? 10. What are metadata? 11. Explain why database design is important. 12. What are the potential costs of implementing a database system? 13. Use examples to compare and contrast unstructured and structured data. Which type is more prevalent in a typical business environment? 14. What are some basic database functions that a spreadsheet cannot perform 15. What common problems do a collection of spreadsheets created by end users share with the typical file system? 16. Explain the significance of the loss of direct, hands-on access to business data that users experienced with the advent of computerized data repositories. Problem Solutions Given the file structure shown in Figure P1.1, answer Problems 1 - 4. FIGURE P1.1 The File Structure for Problems 1-4 PROJECT_CODE PROJECT_MANAGER MANAGER_PHONE MANAGER_ADDRESS 21-5Z Holly B. Parker 904-338-3416 3334 Lee Rd., Gainesville, FL 37123 25-2D Jane D. Grant 615-898-9909 218 Clark Blvd., Nashville, TN 36362 25-5A George F. Dorts 615-227-1245 124 River Dr., Franklin, TN 29185 25-9T Holly B. Parker 904-338-3416 3334 Lee Rd., Gainesville, FL 37123 27-40 George F. Dorts 615-227-1245 124 River Dr., Franklin, TN 29185 29-2D Holly B. Parker 904-338-3416 3334 Lee Rd., Gainesville, FL 37123 31-7P William K. Moor 904-445-2719 216 Morton Rd., Stetson, FL 30155 PROJECT_BID_PRICE 16833460.00 12500000.00 32512420.00 21563234.00 10314545.00 25559999.00 56850000.00 1. How many records does the file contain? How many fields are there per record? 2. What problem would you encounter if you wanted to produce a listing by city? How would you solve this problem by altering the file structure? 3. If you wanted to produce a listing of the file contents by last name, area code, city, state, or zip code, how would you alter the file structure? 1 Topic 1 Database Systems 4. What data redundancies do you detect? How could those redundancies lead to anomalies? FIGURE P1.5 The File Structure for Problems 5-8 PROJ_NUM PROJ_NAME EMP_NUM EMP_NAME JOB_CODE JOB_CHG_HOUR PROJ_HOURS EMP_PHONE 1 Hurricane 101 John D. Newson EE CC 85.00 13.3 653-234-3245 1 Hurricane 105 David F. Schwann CT 60.00 16.2 653-234-1123 1 Hurricane 110 Anne R. Ramoras CT 60.00 14.3 615-233-5568 amics 00 2 Coast 101 John D. Newson EE 85.00 www 19.8 653-234-3254 2 Coast 108 June H. Sattlemeir EE 85.00 17.5 905-554-7812 3 Satellite 110 Anne R. Ramoras CT 62.00 11.6 615-233-5568 3 Satellite 105 David F. Schwann CT 26.00 23.4 653-234-1123 3 Satelite 123 Mary D. Chen EE 85.00 19.1 615-233-5432 3 Satellite 112 Alecia R. Smith BE 85.00 20.7 615-678-6879 5. Identify and discuss the serious data redundancy problems exhibited by the file structure shown in Figure P1.5. 6. Looking at the EMP NAME and EMP PHONE contents in Figure P1.5, what change(s) would you recommend? 7. Identify the various data sources in the file you examined in Problem 5. 8. Given your answer to Problem 7, what new files should you create to help eliminate the data redundancies found in the file shown in Figure P1.5? FIGURE P1.9 The File Structure for Problems 9-10 TTh 1:00-215 BUILDING_CODE ROOM_CODE TEACHER_LNAME TEACHER_FNAME TEACHER_INITIAL DAYS_TIME KOM 204E Williston Horace G MWF 8:00-8:50 KOM 123 Cordoza Maria L MWF 8:00-8:50 LDB 504 Patroski Donald Donald J KOM 34 Hawkins Anne w MF 10:00-10:50 JKP 2258 Risell son James wide TTh 9:00-10:15 LDE 301 Robertson acolo Jeanette P TTH 9:00-10:15 KOM 204E Cordoza Maria 1 MWF 9:00-9:50 9 LDE 504 Williston Horace G TTh 1:00-2 15 KOM 34 Cordoza Maria L MWF 11:00-11:50 LDE 504 Patroski Donald J J MWF 2:00-2:50 9. Identify and discuss the serious data redundancy problems exhibited by the file structure shown in Figure P1.9. (The file is meant to be used as a teacher class assignment schedule. One of the many problems with data redundancy is the likely occurrence of data inconsistencies - that two different initials have been entered for the teacher named Maria Cordoza) 10. Given the file structure shown in Figure P1.9, what problem(s) might you encounter if building KOM were deleted? 2
