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

Silverston c03.tex V2 - 11/21/2008 2:59am Page 124

124 Chapter 3 ■ Using Roles: How Parties Are Involved

model, they may be better off picking either a specific or generalized

style of modeling depending on what is needed for the particular situa-

tion, instead of using this type of hybrid style.

Instead of having one model with two different alternatives, there

are some advantages to having two different data models: a very spe-

cific model showing the roles in whatever way can be best communi-

cated and validated with business representatives and another architec-

tural data model for technical audiences that is more generalized and is

designed to be the basis for the database design. By having two differ-

ent models, there is more leverage to create these models exactly as one

needs.

Synopsis

In this section we described a pattern that supports both the flexible modeling

of contextual roles and the specific modeling of contextual roles. The pattern

created in Figure 3-11 was constructed by merging the Level 2 Contextual

Role Pattern with the Level 3 Contextual Role Pattern. This style of modeling

is very powerful because it provides a method for understanding information

requirements using the specific style of model as well as providing a stable,

flexible foundation for a database design using the flexible style of modeling.

This pattern means that a data professional does not have to maintain two

different ...