OLAP or online analytical processing which aims in analyzing the huge amount of data of a company or other organization accumulates during its day-to-day business. The objective is to prepare strategic decisions and to gain more insight into the nature of the operations the organization participates in. Corresponding applications range from online shops recommending popular products based on the browsing behavior of their customers up to International Corporation trying to identify new profitable market segments in their customer relationship database.
Respective online analytical processing systems should cope with huge volumes of data and also it should allow for short response times in order to facilitate interactive usage. They must also be capable to scale, this means, to be easily extensible with the increasing data volumes accumulated. Furthermore, the requirement that the data analyzed should be up-to-date is becoming more and more important. However, not only are these contrary requirements, but they also run counter to the performance requirements of the everyday business.
Most OLAP systems nowadays are kept separated from mission critical systems. This means that they offer a compromise between 'up-to-dateness', i.e., freshness of data, and query response rimes. The data needed is propagated into the OLAP system only on a regular basis, preferable when not slowing down day-to-day business, e.g., during nights or weekends. OLAP users have no alternative but to analyze stale data.
But a decision support system which could provide decision makers insight into up-to-date data Tiot off the press', would open exciting new possibilities. A stock broker, for example, could analyze current trends in the market on-line. For e-commerce, the personalization of web shops could be much improved by more complex analysis of current browsing behavior. Even for the so-called 'old economy new perspectives open up, because the update window has already become drastically small in a 24/7 setting of a worldwide operating company. However, up to now there is no solution as to how to meet these performance and freshness requirements at the same time.