Special section on spatial and temporal databases

This section of the issue hosts extended versions of the four best papers of the 11th International Symposium on Spatial and Temporal Databases (SSTD 2009). The proceedings of the symposium are published by Springer, as volume 5644 of the series Lecture Notes in Computer Science. More information about it can be found at http://www.springeronline.com/978-3-642-02981-3. For the first time in the SSTD series, the best paper of the symposium was awarded and a few high quality papers were selected and the authors were invited to submit extended versions of their work to Geoinformatica. The paper Spatial Skyline Queries: Exact and Approximation Algorithms, by MuWoong Lee, Wanbin Son, Hee-Kap Ahn, Seung-won Hwang, is an extension of the paper “Spatial Skyline Queries: An Efficient Geometric Algorithm,” by the same authors, which received the best paper award at the symposium. The paper deals with spatial skyline; a query which retrieves the subset of objects in space that are not ‘spatially dominated’ by others with respect to their distances to a set of pivot points. The authors propose a simple and efficient algorithm for spatial skyline evaluation, which correctly computes the result and at the same time it is very efficient compared to previous solutions. Compared to the paper presented at the symposium, the extended version includes additional analytical results and comparison experiments with previous work. In addition, an extension of the proposed approximation algorithm is developed to trace skyline changes, for the case where one of the query points moves in one direction.