This is the last Module that we will review for the regular semester. We review this module during the last scheduled face to face meeting of the regular semester. There are no scheduled assignments associated with this module. We will only examine the many highlights concerning the concepts, design, implementation and maintenance of Data Marts and Data Warehouses.

There is a more detailed description of Data Warehouses in PDF File titled "dwh Overview" in this Module. There are also several links to Websites that also describe in detail Data Warehouses and Data Marts. A couple of the Websites also contain guided tutorials on building a small Data Warehouse from scratch. The study of Data Warehousing is one of my favorite topics. Unfortunately, this introduction to database course provides in its schedule only small amount of time to examine this growing technology in Database Management.

One of the tutorial links that I like is the "Code Project" Link. This tutorial has very good descriptions, illustrations, and even SQL code that implements a small and simple Data Mart. This is the tutorial that we practice with in class.

Understanding a Data Warehouse

A data warehouse is a database, which is kept separate from the organization's operational database.

A data warehouse acts as a back-end for Business Intelligence. A Data Warehouse is a storage place for data. It is used to store current and historical information. According to Bill Inmon, “A warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data in support of management’s decision making process”.

A Data warehouse allows business users to access critical data from a single source enabling them to take quick decisions on issues. A decision maker need not waste time retrieving data from multiple sources.

Another important advantage of a data warehouse is that business executives can query the data themselves with minimal or no support from IT which in turn saves money and time.