In this chapter we provide an introduction to data warehousing. It is sensible as a starting point, therefore, to introduce data warehousing using “first generation” principles so that we can then go on to explore the issues in order to develop a “second generation” architecture.
Data warehousing relates to a branch of a general business subject known as decision support. So in order to understand what data warehousing is all about, we must first understand the purpose of decision support systems (DSS) in general.
Decision support systems have existed, in different forms, for many years. Long before the invention of any form of database management systems (DBMS), information was being extracted from applications to assist managers ...