Normalization is a formal technique that can be used at any stage of database design.
However, in this section we highlight two main approaches for using normalization, as
illustrated in Figure 13.1. Approach 1 shows how normalization can be used as a bottomup
standalone database design technique while Approach 2 shows how normalization can
be used as a validation technique to check the structure of relations, which may have been
created using a top-down approach such as ER modeling. No matter which approach is
used the goal is the same that of creating a set of well-designed relations that meet the data
requirements of the enterprise.
Figure 13.1 shows examples of data sources that can be used for database design.
Although, the users’ requirements specification (see Section 9.5) is the preferred data
source, it is possible to design a database based on the information taken directly from
other data sources such as forms and reports, as illustrated in this chapter and the next.