The schema design often used, a star schema, lets youaccess facts
quite flexibly along key dimensions or ???lookup??? values. (The star schema is
described in more detail later in this chapter.) For instance, a data warehouse
user may want to compare the total amount of sales, which comes from a fact
table, by region, store in the region, and items, all of which can be considered
key dimensions. Today??™s data warehouses often feature a hybrid schema that is a
combination of the star schema common in previous-generation data marts with
third normal form schema for detailed data that is common in OLTP systems
and enterprise data warehouses.
224 | Chapter 10: Oracle Data Warehousing and Business Intelligence
The Evolution of Business Intelligence
Gathering business intelligence is not a new idea. The use of corporate data for strategic
decision-making beyond simple tracking and day-to-day operations has been
going on for almost as long as computing itself.
Quite early, builders and users of operational systems recognized potential business
benefits of analyzing the data in complementary systems.
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