OLAP

The term stands for ‘On-Line Analytical Processing’. Unfortunately, this is neither a meaningful definition nor a description of what OLAP means. It certainly gives no indication of why you would want to use an OLAP tool, or even what an OLAP tool actually does. And it gives you no help in deciding if a product is an OLAP tool or not. It was simply chosen as a term to contrast with OLTP, on-line transaction processing, which is much more meaningful.

First we need to decide which products fell into the category. Deciding what is an OLAP has not got any easier since then, as more and more vendors claim to have ‘OLAP compliant’ products, whatever that may mean (often they don’t even know). It is not possible to rely on the vendors’ own descriptions and membership of the long-defunct OLAP Council was not a reliable indicator of whether or not a company produces OLAP products. For example, several significant OLAP vendors were never members or resigned, and several members were not OLAP vendors. Membership of the instantly moribund replacement Analytical Solutions Forum was even less of a guide, as it was intended to include non-OLAP vendors.

The Codd rules also turned out to be an unsuitable way of detecting ‘OLAP compliance’, so we were forced to create our own definition. It had to be simple, memorable and product-independent, and the resulting definition is the ‘FASMI’ test. The key thing that all OLAP products have in common is multidimensionality, but that is not the only requirement for an OLAP product.