Spatio-Temporal Data Warehousing: a Survey

Geographic Information Systems (GIS) have been extensively used in various application domains, ranging from economical, ecological and demographic analysis, to city and route planning. Nowadays, organizations need sophisticated GIS-based Decision Support System (DSS) to analyze their data with respect to geographic information, represented not only as attribute data, but also in maps. Thus, vendors increasingly integrating their products, and the concept of SOLAP (Spatial OLAP) arose. Also, in the last years, and motivated by the explosive growth in the use of PDA devices, the field of moving object data has been receiving attention from the GIS community. However, not much has been done in providing moving object databases with OLAP functionality. In the first part of this paper we survey the literature on the field of Spatial OLAP. We then move to the field of SpatioTemporal OLAP, in particular addressing the problem of trajectory analysis. We finally provide an in-depth comparative analysis between two proposals in the field: the GeoPKDD project proposal (that makes use of the Hermes database), and Piet, a proposal developed at the University of Buenos Aires, Argentina.