Kenneth C. Laudon,Jane P. Laudon Management Information System 12th Edition pdf

data warehouse 

is a database that stores current and historical data of

potential interest to decision makers throughout the company. The data

originate in many core operational transaction systems, such as systems 

for sales, customer accounts, and manufacturing, and may include data 

from Web site transactions. The data warehouse consolidates and standardizes

information from different operational databases so that the information can be

used across the enterprise for management analysis and decision making.

Figure 6-12 illustrates how a data warehouse works. The data warehouse

makes the data available for anyone to access as needed, but it cannot be

altered. A data warehouse system also provides a range of ad hoc and

standardized query tools, analytical tools, and graphical reporting facilities.

Many firms use intranet portals to make the data warehouse information

widely available throughout the firm.

Catalina Marketing, a global marketing firm for major consumer packaged

goods companies and retailers, operates a gigantic data warehouse that includes

three years of purchase history for 195 million U.S. customer loyalty program

members at supermarkets, pharmacies, and other retailers. It is the largest

loyalty database in the world. Catalina’s retail store customers analyze this

database of customer purchase histories to determine individual customers’

buying preferences. When a shopper checks out at the cash register of one of

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Catalina’s retail customers, the purchase is instantly analyzed along with that

customer’s buying history in the data warehouse to determine what coupons

that customer will receive at checkout along with a receipt. 

The U.S. Internal Revenue Service (IRS) maintains a Compliance Data

Warehouse that consolidates taxpayer data that had been fragmented among

many different legacy systems, including personal information about taxpay-

ers and archived tax returns. These systems had been designed to process tax

return forms efficiently but their data were very difficult to query and

analyze. The Compliance Data Warehouse integrates taxpayer data from

many disparate sources into a relational structure, which makes querying

and analysis much easier. With a complete and comprehensive picture of

taxpayers, the warehouse helps IRS analysts and staff identify people who

are most likely to cheat on their income tax payments and respond rapidly to

taxpayer queries.

D a t a   M a r t s

Companies often build enterprise-wide data warehouses, where a central data

warehouse serves the entire organization, or they create smaller, decentral-

ized warehouses called data marts. A