A powerful, easy-to-use querying environment is without doubt one of the most important components in a multidimensional database. Its effectiveness is influenced by many aspects, both logical (data model, integration, policy of view materialization, etc.) and physical (multidimensional or relational storage, indexes, etc.). Multidimensional querying is often based on the core concepts of multidimensional data modeling, namely the metaphor of the data cube and the concepts of facts, measures and dimensions (Agrawal, Gupta, & Sarawagi, 1997; Gyssens & Lakshmanan, 1997). In contrast to conventional transactional environments, multidimensional querying is often an exploratory process, performed by navigating along dimensions and measures, increasing/decreasing the level of detail and focusing on specific subparts of the cube that appear “promising” for the required information.
On the complexity of queries in the logical data model