FIRST GENERATION DATA WAREHOUSES

only for RuBoard - do not distribute or recompile

FIRST GENERATION DATA WAREHOUSES

Historically, the first-generation data warehouses were built on certain principles that were laid down by gurus in the industry. This author recognizes two great pioneers in data warehousing: Bill Inmon and Ralph Kimball. These two chaps, in my view, have done more to advance the development of data warehousing than any others. Although many claim to have been doing data warehousing long before it was ever called data warehousing, Inmon and Kimball can realistically claim to be the founders because they alone laid down the definitions and design principles that most practitioners are aware of today. Even if their guidelines are not followed precisely, it is still common to refer to Inmon's definition of a data warehouse and Kimball's rules on slowly changing dimensions.

Chapter 2 of this book is an introduction to data warehousing. In some respects it should be regarded as a scene-setting chapter, as it introduces data warehouses from first principles by describing the following:

• Need for decision support

• How data warehouses can help

• Differences between operational systems and data warehouses

• Dimensional models

• Main components of a data warehouse

Chapter 2 lays the foundation for the evolution to the second-generation data warehouses.

only for RuBoard - do not distribute or recompile