Spatio-temporal Aggregations in Trajectory Data Warehouses

In this paper we investigate some issues related to the design of a simple Data Warehouse (DW), storing several aggregate measures about trajectories of moving objects. First we discuss the loading phase of our DW which has to deal with overwhelming streams of trajectory observations, possibly produced at different rates, and arriving in an unpredictable and unbounded way. Then, we focus on the measure presence, the most complex measure stored in our DW. Such a measure returns the number of trajectories that lie in a spatial region during a given temporal interval. We devise a novel way to compute an approximate, but very accurate, presence aggregate function, which algebraically combines a bounded amount of measures stored in the base cells of the data cube.

[1]  Thomas Brinkhoff,et al.  A Framework for Generating Network-Based Moving Objects , 2002, GeoInformatica.

[2]  Jeffrey Scott Vitter,et al.  Data cube approximation and histograms via wavelets , 1998, CIKM '98.

[3]  Surajit Chaudhuri,et al.  An overview of data warehousing and OLAP technology , 1997, SGMD.

[4]  Yixin Chen,et al.  Stream Cube: An Architecture for Multi-Dimensional Analysis of Data Streams , 2005, Distributed and Parallel Databases.

[5]  Chengyang Zhang,et al.  Advances in Spatial and Temporal Databases , 2015, Lecture Notes in Computer Science.

[6]  Nikos Pelekis,et al.  Nearest Neighbor Search on Moving Object Trajectories , 2005, SSTD.

[7]  Renzo Orsini,et al.  Approximate Aggregations in Trajectory Data Warehouses , 2007, 2007 IEEE 23rd International Conference on Data Engineering Workshop.

[8]  Dieter Pfoser,et al.  Novel Approaches in Query Processing for Moving Object Trajectories , 2000, VLDB 2000.

[9]  Philippe Flajolet,et al.  Probabilistic Counting Algorithms for Data Base Applications , 1985, J. Comput. Syst. Sci..

[10]  Jeffrey Considine,et al.  Spatio-temporal aggregation using sketches , 2004, Proceedings. 20th International Conference on Data Engineering.

[11]  Panos Kalnis,et al.  Indexing spatio-temporal data warehouses , 2002, Proceedings 18th International Conference on Data Engineering.

[12]  Hamid Pirahesh,et al.  Data Cube: A Relational Aggregation Operator Generalizing Group-By, Cross-Tab, and Sub-Totals , 1996, Data Mining and Knowledge Discovery.