Objectives of Good Database Design

Objectives of Good Relational Database Design:

There are many distinct objectives that you must achieve in order to design a good, sound, structured database. You can avoid many of the problems you may encounter by keeping the following objectives in mind and constantly focus on these whilst designing your database.

§  The database supports both required and ad hoc (unplanned) information retrieval. The database must be designed to store the data necessary to support information requirements defined during the design process and any possible ad hoc queries that may be posed by the users.

§  The tables are constructed properly and efficiently. Each table in the database must represent a single subject only and should be composed of relatively distinct fields which keep redundant data to an absolute minimum and should be identified throughout the database by a field with unique values.

§  Data integrity is imposed at the field, table and relationship levels. These levels of integrity help guarantee that the data structures and their values will be valid and as accurate as possible at all times.

§  The database should support business rules relevant to the organization it is designed for.The data must provide accurate information that is always meaningful to the business.

§  The database should lend itself to future growth and development. The database structure should be easily modifiable and expendable as the information requirements of the business continue to change and grow.

You may find it difficult at times to fulfill all of these objectives, but you'll certainly be pleased with your final database design structure once you've met them.

Benefits of Good Database Design:

The time that you invest in designing a sound, well structured database is time well spent. Good database design saves you time in the long run because you do not have to spend time constantly revamping a quickly and poorly designed structure. You gain the following benefits when you apply good design techniques:

§  The database structure is easy to modify and maintain. Modifications you make to a table or field will not adversely affect other tables or fields in the database.

§  The data is easy to modify. Changes that you make to the value of a given field will not adversely affect the values of other fields within the table. Furthermore, a well-designed database keeps duplicate fields to an absolute minimum, so you typically modify a particular data value in one field only.

§  Information is easy to retrieve. You should be able to create queries easily due to well constructed tables and the relationships between them are correctly established.

§  End-User applications are easy to develop and build. You can spend more time on programming and addressing the data manipulation tasks at hand, instead of working around the inevitable problems that will arise when you work with a poorly designed database.