In this chapter, many different topics will be addressed. The purpose of this chapter is to tie together many of the concepts that are required to make the data warehouse successful.
The subject of data warehousing — at the heart of the corporate information factory (CIF) and business intelligence — is a complex subject with many facets. This chapter addresses some of the topics that do not comfortably fit with other topics that have been addressed elsewhere.
One of the questions frequently asked and often misunderstood is where do the requirements for the building of the data warehouse come from? In truth, the requirements for the building of the data warehouse come from a data model. End-user requirements are a part of the picture, although the end-user requirements enter the picture indirectly. To understand how end-user requirements enter into the usage of data found in the data warehouse, consider the following design considerations for the data warehouse.
The data warehouse is shaped by a data model. The data model has different levels. The data model typically has the high-level data model, the midlevel data model, and the low-level data model.
The high-level data model shows how the major subject areas of the data warehouse should be divided. Typical high-level subject areas are customer, product, shipment, order, part number, and so forth.
The midlevel ...