par Malinowski Gajda, Elzbieta ;Zimanyi, Esteban
Référence Data & knowledge engineering, 59, 2, page (348-377)
Publication Publié, 2006-11
Article révisé par les pairs
Résumé : Hierarchies are used in data warehouses (DWs) and on-line analytical processing (OLAP) systems to see data at different levels of detail. However, many kinds of hierarchies arising in real-world situations are not addressed by current OLAP systems. Further, there is still no agreement on a conceptual model for DW and OLAP design that offers both a graphical representation and a formal definition. In this paper, we formally define the MultiDimER model, a conceptual multidimensional model that allows to represent facts with measures as well as the different kinds of hierarchies already classified in our previous work [E. Malinowski, E. Zimányi, OLAP hierarchies: a conceptual perspective, in: Proceedings of the 16th International Conference on Advanced Information Systems Engineering, 2004, pp. 477-491]. We also present the mapping of such hierarchies to the relational model, as well as their implementation in commercial DW products. © 2005 Elsevier B.V. All rights reserved.