For example, breaking up the phone number into the area code 653 and the phone number 234-3245. 7. Identify the various data sources in the file you examined in Problem 5. Employee data such as names and phone numbers. Project data such as project names. Job data such as the Job charge per hour. If you start with an EMPLOYEE file, the Job charge per hour does not belong in that file The project hours, which are the hours worked by the employee for that project. 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 Pl . Data redundancy can be controlled by storing the data in separate tables. Each of these tables would be named to indicate its contents, I. E. , we would recommend the creation of four tables named PROJECT, EMPLOYEE, JOB, and CHARGE, 9. Identify and discuss the serious data redundancy problems exhibited by the file 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 Corpora. ) FIGURE Pl . 9 The File structure for problems 9-10 he teacher characteristics occur multiple times in this file.
For example, the teacher named Maria Corpora’s first name, last name, and initial occur three times. If changes must be made for any given teacher, those changes must be made multiple times. All it takes is one incorrect entry or one forgotten change to create data inconsistencies.