What to Expect in Data Warehousing

by Penny P
Data warehouses play a critical role in corporation/institutions. They allow users to quickly retrieve data to be used for data mining or for data analysis tools. The results that they get from these tools are then used to support business decisions that would be made. The authors of the article designed a case study that would help beginners understand the basics of data warehousing. Using the enrollment data from Universities, the main objective was to prepare the data for a mining system that would be used for predicting student enrollment.

In the design process of a data warehouse, two important steps include: 1) clearly identifying the objective of the data warehousing project and 2) determining the user requirements. Two types of summary reports that they are looking for include 1) the enrollment reports for graduate and undergraduate students for the last 30 years and 2) the annual reports of the demographic impact factors on enrollment. The design that the authors use are based on a star schema with each group placed in a dimension table. Aggregation was also used to forecast the number of students for next term. The authors gave two strategies on how aggregation could be used: 1) aggregation based on the fact that the tables should be equal to the number of aggregate functions or 2) aggregation based on the idea that an aggregate table is designed to be a dimension table. That way, one of the aggregated tables will contain keys to multiple aggregate functions that will be referenced by the base fact table. Aggregation helps improve the performance of a data warehouse because it reduces the number of scans on the records. As a result, it helps make the queries more efficient.

This article started out with some basic info about data warehousing and how it is used to help companies make business decisions. When the authors talked about the design, it really described how complex data warehousing could be. There are so many things that the designers have to consider and the idea of working with multiple tables and dimensions makes it sound like a very difficult task. Data warehousing is definitely a great tool for businesses to use and it looks like it holds many benefits for the users. But since we are still new to this, designing one seems like it will be quite a challenge.



Kulkarni, M., Lu, M., Zhang, D. (2010). “A Case-Based Data Warehousing Courseware.” Information Reuse and Integration (IRI). (August 2010) P. 245-248. Retrieved from http://0-ieeexplore.ieee.org.opac.library.csupomona.edu/stamp/stamp.jsp?tp=&arnumber=5558932.

2 thoughts on “What to Expect in Data Warehousing”

  1. I enjoyed reading your article. After taking a good look at it, I realized that the example was mildly similar to the one we have in our book and have discussed in class. The only difference is that your article also talks about using predictive or analytic processes. There is already business intelligence software out there for business processes but not so much for schools. It somewhat relates to my article in the sense that Oracle is also taking a new approach to combine their analytical software with Taleo's human resource management applications. It may just be a matter of time before this is adapted for education.

  2. This is yet another great example of how data storage entity's, such as, a data warehouse can gather analytical information for the real world. I am not too familiar with the design of a data warehouse and I would assume it is somewhat similar in designing a regular database to some degree. I can also see how it looks like the design of one can be very complex but I am sure just like any other skill, "practice makes perfect". This was a good article to let me know what to expect and I am looking forward to learning more about this subject.

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