Objectives Of Data Base

The general theme behind a database is to handle information as an integrated whole. There is none of the artificiality that is normally embedded in separate files or applications. A database is a collection of interrelated fated data stored with minimum redundancy to serve many users quickly and efficiently. The general objective is to make information access easy, quick, inexpensive, and flexible' for the user. In data base design, several specific objectives are considered:

1. Controlled redundancy. Redundant data occupies space and, therefore, is wasteful. If versions of the same data are in different phases of updating, the system often gives conflicting information. A unique aspect of data base design is storing data only once, which controls redundancy and improves system performance.

2. Ease of learning and use. A major feature of a user-friendly data base package is how easy it is to learn and use. Related to this point is that a database can be modified without interfering with established ways of using the data.

3. Data independence. An important data base objective is changing hardware and storage procedures or adding new data without having to rewrite application programs. The database should be "tunable" to improve performance without rewriting programs.

4. More information al low cost. Using, storing, and modifying data at low cost are important. Although hardware prices are falling, software and programming costs are on the rise. This means that programming and software enhancements should be kept simple and easy to update.

5. Accuracy and integrity. The accuracy of a data base ensures that data quality and contel1t remain constant." Integrity controls detect data inaccuracies where they occur.

6. Recovery from failure. With multiuser access to a data base, the system must recover quickly after it is down with no loss of transactions. This objective also helps maintain data accuracy and integrity.

7. Privacy and security. For data to remain private, security measures must be taken to prevent unauthorized access. Data base security means that data are protected from various forms of destruction; users must be positively identified and their actions monitored.

8. Performance. This objective emphasizes response time to inquiries suitable to the use of the data. How satisfactory the response time is depends on the nature of the user-data base dialogue. For example, inquiries regarding airline seat availability should be handled in a few seconds. On the other extreme, inquiries regarding the total sale of a product over the past two weeks may be handled satisfactorily in 50 seconds