1. Quiz 12 Data Warehouses Quoc Anh Tran Timothy O’Brien

2.  1. Which one of the following applications/activities is typical of a data warehouse?  Since data warehouses are used to collect and store historical and present data of a business, management can use it to make business decisions. Answer B comes closest to this definition.  2. Which of the following may occur in a star schema?  A start schema may contain one to many relationships (p. 605). The answer is therefore B.

3.  3. Which clause of SQL SELECT statement may use the CUBE operations?  Only GROUP BY statement may use the CUBE operations. Answer A.  4. Which of the following statements is not true about populating a data warehouse:  Both A and C are true since data warehouses store data critical for business decision making and they can come from both internal and external sources.  The answer is therefore B.

4.  5. In maintaining a data warehouse, which of the following is not a task in the PREPARATION phase:  Merging is not in the preparation phrase since it is a in the INTEGRATION phase  6. Why are operational databases not particularly suited for decision support applications?  Operational Databases contain only current data, it cannot tell the management what happened at some earlier point in time. Thus, it cannot show information critical for business decision making, such as trends etc…  Only one source  Does not have complete picture