On-Line Analytical Processing Queries for Extensible Mark-up Language

On-Line Analytical Processing (OLAP) enables analysts to gain insight into data through fast access to a variety of possible views on information, organized in a dimensional model. The increasing use of Extended Mark-up Language (XML) suggests that the WEB data will most often be available in XML format. In this article, we present XML data cube, a well-founded approach to represent OLAP data using XML. XML data cube allows OLAP data to be presented using XML along with dimensional data and enables the use of external XML data for selection and grouping. Our novel query language XRQL will be used to express OLAP queries in a natural way. The XRQL queries capture the flavour of SQL queries while offering constructs for navigation, XML data construction and grouping