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What Is OLAP
OLAP stands for On-Line Analytical Processing. The first attempt to provide a definition to
OLAP was by Dr. Codd, who proposed 12 rules for OLAP. Later, it was discovered that this
particular white paper was
sponsored by one of the OLAP tool vendors, thus causing it to lose objectivity. The OLAP Report
has proposed the FASMI test, Fast Analysis of Shared
Multidimensional Information. For a more detailed description of both
Dr. Codd's rules and the FASMI test, please visit The OLAP Report.
For people on the business side, the key feature out of the above list is "Multidimensional."
In other words, the ability to analyze metrics in different dimensions such as time, geography,
gender, product, etc. For example, sales for the company is up. What region is most responsible
for this increase? Which store in this region is most responsible for the increase? What
particular product category or categories contributed the most to the increase? Answering these
types of questions in order means that you are performing an OLAP analysis.
Depending on the underlying technology used, OLAP can be braodly divided into two different camps:
MOLAP and ROLAP. A discussion of the different OLAP types can be found in the MOLAP, ROLAP, and HOLAP section.