Data Warehousing Fundamentals for IT Professionals

CHAPTER 2

DATA WAREHOUSE: THE BUILDING BLOCKS

CHAPTER OBJECTIVES

• Review formal definitions of a data warehouse
• Discuss the defining features
• Distinguish between data warehouses and data marts
• Review the evolved architectural types
• Study each component or building block that makes up a data warehouse
• Introduce metadata and highlight its significance

As we have seen in the last chapter, data warehousing has evolved as part of business intelligence for the enterprise. In the data warehouse you integrate and transform enterprise data into information suitable for strategic decision making. You take all the historic data from the various operational systems, combine this internal data with any relevant data from outside sources, and pull them together. You resolve any conflicts in the way data resides in different systems and transform the integrated data content into a format suitable for providing information to the various classes of users. Finally, you supplement with information delivery methods.

In order to set up this information delivery system, you need different components or building blocks. These building blocks are arranged together in the most optimal way to serve the intended purpose. They are arranged in a suitable architecture. Before we get into the individual components and their arrangement in the overall architecture, let us first look at some fundamental features of the data warehouse.

Bill Inmon (1996, p. 33), considered to be the father of data warehousing ...