One post tagged with "design"

Normalisation is the process of eliminating the redundancy, minimising the use of null values and prevention of the loss of information by establishing relations and ensuring data integrity.

Data should only be stored once and avoid storing data that can be calculated from other data already held in the database. During the process of normalisation redundancy must be removed, but not at the expense of breaking data integrity rules.

The removal of redundancy helps to prevent insertion, deletion, and update errors, since the data is only available in one attribute of one table in the database.