From a Procedural to a Visual Query Language for OLAP

We address the issue of designing effective query languages for OLAP databases. The basis of our investigation is MD, a new data model for multidimensional databases that, unlike other multidimensional models, is independent of any specific implementation and as such provides a clear separation between practical and conceptual aspects. In this framework, we present and compare two query languages, based on different paradigms, for OLAP databases. The first language is algebraic and provides an effective way to manipulate multidimensional data in a procedural fashion. Although this language is clean and powerful, it is clearly not suited for final users. We therefore propose a high-level graphical language that allows the user to specify analytical queries in a natural and intuitive way. It turns out that the two languages have the same expressive power.