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

Silverston c09.tex V2 - 11/21/2008 3:16am Page 513

Data Warehouse Models 513

In conclusion, the data team created a very flexible data model that attempted

to support the future needs of the business and maintain a history of changes

in relationships. In fact, they also decided in this data warehouse data model

to use the same level of generalization throughout the model, namely, level 3

patterns. In doing this, they believed that they would give up some simplicity

of implementation, but in practice, because the models were very consistent,

there was a great benefit in being able to consistently manage the data in

the data warehouse and reuse routines. For instance, they noticed that the

part of the data model that supported flexible classification of customer

information was the same pattern that supported product classification (or

any other classification). This meant that the routines and code supporting

product classifications could be reused, with some modification, to support

any classification. They also noticed that some of the constructs that were

reused, such as the status pattern and the contextual role pattern, had useful

code and expertise surrounding them in the customer application that they

could leverage. Finally, developing the data warehouse model based on the

enterprise data model is a well known ‘best practice’ and seemed quite natural

and intuitive. Some of the data team was involved ...