Database Reference
In-Depth Information
24.2 Rationale for Data Warehousing
Data warehousing is a technology that is fast enhancing more traditional decision support
systems (DSS), because of the added flexibility and benefits that the new technology
brings. Let us briefly examine the problems that DSS end users tend to have from two
perspectives — user constraints and information system (IS) constraints.
User Constraints:
In the absence of data warehousing, users of traditional decision
support systems developed using the traditional application-driven approach, commonly
complained of the following difficulties:
•
Difficulty in finding and accessing information needed
•
Difficulty in understanding information found
•
Information obtained is not as useful as expected
IS Constraints:
In the absence of data warehousing, IS personnel also complained of
a variety of problems:
•
Developing copy programs is often very challenging
•
Maintaining copy programs and copy databases presents serious
integrity and work scheduling problems
•
Data storage volumes tend to grow rapidly
•
Database administration also tends to become quite complex
The solution to the above-mentioned problems is the implementation of a data
warehouse. A data warehouse provides the decision support benefits that a traditional
DSS provides, while providing more flexibility for expansion beyond the confines of the
company. This is so for two reasons:
•
The data warehouse has the capacity to attract interest in
the salient facts about the organization, without providing
unnecessary details.
•
While companies may be hesitant about putting their transaction
database(s) into the public domain (due to security and
confidentiality concerns), they are more likely to be willing to
put their data warehouse into the public domain (via the World
Wide Web).
24.3 Characteristics of a Data Warehouse
In the definition of a data warehouse, a number of terms were deliberately highlighted.
These terms convey important characteristics about a data warehouse. These will be
clarified in the next subsection. Next, we will examine what kind of data that is typically
stored in a data warehouse. We also examine the processing requirements of a data
warehouse. Finally, we will review twelve rules that govern data warehouses.
