The Data Model Resource Book, Volume 3: Universal Patterns for Data Modeling

Silverston c05.tex V2 - 11/21/2008 3:04am Page 230

230 Chapter 5 ■ Types and Categories: the Classification of Data

What Are the Weaknesses of the Pattern?

The weaknesses of this pattern are as follows:

It has the same weaknesses as the Level 3 Classification Pattern. For

example, it is not effective for using as a part of the statement of scope,

or for gathering and validating data requirements for nontechnical audi-

ences. It does not capture specific business rules, data or

relationships for specific types of categories or types. It also allows data

modelers to use ‘‘catch all’’ categories without doing detailed analysis.

It is very complex and difficult to understand. It is a complex pattern

that introduces many-to-many recursive relationships and schemes. It

can be difficult even for seasoned data professionals to understand and

communicate this pattern to the business or other IT professionals.

It may be overkill if only one-to-many recursions are needed or if

schemes are not needed. Many times there is only a need to have one-

to-many recursive relationships for categories and category types, so

many-to-many relationships are not necessary. Also, there may not be a

need to capture schemes and the related data providers.

Synopsis

In this pattern we introduced the idea of an ENTITY CATEGORY TYPE

SCHEME. This is where a set of ENTITY CATEGORY TYPE(s) has been

designated by an external or internal organization ...