Accurate design is crucial to the operation of a reliable and efficient information system. Microcomputer technology is now so advanced that the impact of a poor design may not show up as early as in the past; however, when the problems appear they can be severe. The design of a database has to do with the way data is stored and how that data is related. The design process is performed after you determine exactly what information needs to be stored and how it is to be retrieved. The more carefully you design, the better the physical database meets users' needs. In the process of designing a complete system, you must consider user needs from a variety of viewpoints.

Problems Resulting from Poor Design

       The database or application may not function properly.
       Data may be unreliable or inaccurate.
       Performance may be degraded.
       Flexibility may be lost.
The following section explains some common problems resulting from poor database design. The problems can be grouped under two categories: redundant data and modification anomalies.