DATA WAREHOUSE
A data warehouse is a logical collection of information gathered from different operational databases and used to create business intelligence that supports decision making tasks and business analysis activities. Walmart is known for having the biggest data warehouse used, which is larger then 4 Petabytes. Wal-Mart is very secretive about their data warehouse. After achieving a major milestone Teradata, Wal-Mart’s data warehouse supplier, was given permission to announce a few shallow facts about Wal-Mart’s data warehouse.
• Wal-Mart has indeed the world’s largest, non military, database with a size of one-half a petabyte.
• It is the world’s largest data warehouse
Wal-Mart keeps track of 100 million customers buying billions of products every week. Using this data allows Wal-Mart to achieve Always Low Prices. It is the data warehouse that enabled Wal-Mart to become one of the 15 most profitable companies in the world.
Let’s look at some sales questions Wal-Mart’s data warehouse has to answer: • How much orange juice did we sell last year, last month, last week in store X? • Comparing sales data of orange juice in various stores? • What internal factors (position in store, advertising campaigns...) in- fluence orange juice sales? • What external factors (weather...) influence orange juice sales? • Who bought orange juice last year, last month, last week?
A data warehouse really is a Decision Support System (DSS). Providing the data to support business decisions is hole point of a data warehouse. A data warehouse coming from the IT department, or from the higher IT consultants is never going to work if the support from the business side is missing
WalMart shares the same objectives as their suppliers, i.e. to sell more merchandise. To make suppliers as efficient as Wal-Mart itself, suppliers got full access to Wal-Mart’s data warehouse. Of course