ANSWERS TO REVIEW QUESTIONS 1

1. Discuss each of the following terms:
a. Data: Raw facts from which the required information is derived. Data have little meaning unless they are grouped in a logical manner.

b. Field: A character or a group of characters (numeric or alphanumeric) that describes a specific characteristic. A field may define a telephone number, a date, or other specific characteristics that the end user wants to keep track of.

c. Record: A logically connected set of one or more fields that describes a person, place, event, or thing. For example, a CUSTOMER record may be composed of the fields CUST_NUMBER, CUST_LNAME, CUST_FNAME, CUST_INITIAL, CUST_ADDRESS, CUST_CITY, CUST_STATE, CUST_ZIPCODE, CUST_AREACODE, and CUST_PHONE.

d. File: Historically, a collection of file folders, properly tagged and kept in a filing cabinet. Although such manual files still exist, we more commonly think of a (computer) file as a collection of related records that contain information of interest to the end user. For example, a sales organization is likely to keep a file containing customer data. Keep in mind that the phrase related records reflects a relationship based on function. For example, customer data are kept in a file named CUSTOMER. The records in this customer file are related by the fact that they all pertain to customers. Similarly, a file named PRODUCT would contain records that describe products – the records in this file are all related by the fact that they all pertain to products. You would not expect to find customer data in a product file, or vice versa.

2. What is data redundancy, and which characteristics of the file system can lead to it?
Data redundancy exists when there is duplicate data found in a database. Such as, a customer's telephone number being found in the invoice file. Data redundancy is the result of a poorly designed