Discuss the alternative ways that normalization can be used to support database design.

Question

What will be an ideal response?

Answer 1

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 14.1. Approach (1) shows how normalization can be used as a bottom-up 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 14.1 shows examples of data sources that can be used for database design.
Although, the users’ requirements specification (see Section 10.5) 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. Figure 14.1 also
shows that the same data source can be used for both approaches, however, although this is
true in principle, in practice the approach taken is likely to be determined by the size, extent,
and complexity of the database being described by the data sources and by the preference and
expertise of the database designer. The opportunity to use normalization as a bottom-up
standalone technique (Approach 1) is often limited by the level of detail that the database
designer is reasonably expected to manage. However, this limitation is not applicable when
normalization is used as a validation technique (Approach 2) as the database designer only
focuses on part of the database such as a single relation at any one time. Therefore, no matter
what the size or complexity of the database then normalization can be usefully applied.