THE DATA WAREHOUSE - Fundamentals of Database Management Systems - page 336

The Enterprise Data Warehouse
(EDW)
The Data Mart (DM)
Which to Choose: The EDW, the
DM, or Both?
Designing a Data Warehouse
Introduction
General Hardware Co. Data
Warehouse
Good Reading Bookstores Data
Warehouse
Lucky Rent-A-Car Data Warehouse
What About a World Music
Association Data Warehouse?

Building a Data Warehouse
Introduction
Data Extraction
Data Cleaning
Data Transformation
Data Loading
Using a Data Warehouse
On-Line Analytic Processing
Data Mining
Administering a Data Warehouse
Challenges in Data Warehousing
Summary

INTRODUCTION

Generally, when we think about information systems, we think about what are
known as operational or ''transaction processing systems'' (TPS) .Theseare
the everyday application systems that support banking and insurance operations,
manage the parts inventory on manufacturing assembly lines, keep track of airline
and hotel reservations, support Web-based sales, and so on. These are the kinds of
application systems that most people quickly associate with the information systems
field and, indeed, these are the kinds of application systems that we have used as
examples in this topic. The databases that support these application systems must
have several things in common, which we ordinarily take for granted. They must
have up-to-the-moment current data, they must be capable of providing direct access
and very rapid response, and they must be designed for sharing by large numbers of
users.
But the business world has other needs of a very different nature. These needs
generally involve management decision making and typically require analyzing data
that has been accumulated over some period of time. They often don't even require
the latest, up-to-the-second data! An example occurs in the retail store business,
when management has to decide how much stock of particular items they should
carry in their stores during the October-December period this year. Management is
going to want to check the sales volume for those items during the same three-month
period in each of the last five years. If airline management is considering adding
additional flights between two cities (or dropping existing flights), they are going
to want to analyze lots of accumulated data about the volume of passenger traffic
in their existing flights between those two cities. If a company is considering
expanding its operations into a new geographical region, management will want to
study the demographics of the region's population and the amount of competition
it will have from other companies, very possibly using data that it doesn't currently
have but must acquire from outside sources.
In response to such management decision-making needs, there is another class
of application systems, known as ''decision support systems'' (DSS) ,thatare
specifically designed to aid managers in these tasks. The issue for us in this topic
about database management is: what kind of database is needed to support a DSS?