Spatial inverse query processing

Traditional spatial queries return, for a given query object q, all database objects that satisfy a given predicate, such as epsilon range and k-nearest neighbors. This paper defines and studies inverse spatial queries, which, given a subset of database objects Q and a query predicate, return all objects which, if used as query objects with the predicate, contain Q in their result. We first show a straightforward solution for answering inverse spatial queries for any query predicate. Then, we propose a filter-and-refinement framework that can be used to improve efficiency. We show how to apply this framework on a variety of inverse queries, using appropriate space pruning strategies. In particular, we propose solutions for inverse epsilon range queries, inverse k-nearest neighbor queries, and inverse skyline T. Bernecker · T. Emrich · H.-P. Kriegel · M. Renz · A. Züfle ( ) Institute for Informatics, Ludwig-Maximilians-Universität München, Oettingenstr. 67, 80538 München, Germany e-mail: [email protected] T. Bernecker e-mail: [email protected] T. Emrich e-mail: [email protected] H.-P. Kriegel e-mail: [email protected] M. Renz e-mail: [email protected] N. Mamoulis · S. Zhang Department of Computer Science, University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong N. Mamoulis e-mail: [email protected] S. Zhang e-mail: [email protected] 450 Geoinformatica (2013) 17:449–487 queries. Furthermore, we show how to relax the definition of inverse queries in order to ensure non-empty result sets. Our experiments show that our framework is significantly more efficient than naive approaches.