|Bibliography||Lange, Ralph; Dürr, Frank; Rothermel, Kurt: Scalable Processing of Trajectory-Based Queries in Space-Partitioned Moving Objects Databases. |
In: Proceedings of the 16th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM GIS 2008).
University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems).
pp. 1-10, english.
Irvine, CA, USA: ACM, November 5, 2008.
Article in Proceedings (Conference Paper).
|CR-Schema||H.2.8 (Database Applications)|
|Keywords||spatio-temporal indexing; moving objects database; MOD; trajectory-based query; distributed query processing|
Space-partitioned Moving Objects Databases (SP-MODs) allow for the scalable, distributed management of large sets of mobile objects' trajectories by partitioning the trajectory data to a network of database servers. Processing a spatio-temporal query q therefore requires efficiently routing q to the servers storing the affected trajectory segments. With a coordinate-based query - like a spatio-temporal range query - the relevant servers are directly determined by the queried range. However, with trajectory-based queries - like retrieving the distance covered by a certain object during a given time interval - the relevant servers depend on actual movement of the queried object. Therefore, efficient routing mechanisms for trajectory-based queries are an important challenge in SP-MODs. In this paper, we present the Distributed Trajectory Index (DTI) that allows for such efficient query routing by creating an overlay network for each trajectory. We further present an enhanced index called DTI+S. It accelerates the processing of queries on aggregates of dynamic attributes, like the maximum speed during a time interval, by augmenting DTI with summaries of trajectory segments. Our simulations with a network of 1000 database servers show that DTI+S can reduce the overall processing time by more than 98%.
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|Copyright||© ACM, 2008. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Proceedings of the 16th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM GIS '08), pp. 270-279. Irvine, CA, USA. November 2008. http://doi.acm.org/10.1145/1463434.1463474 |
|Department(s)||University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems|
|Project(s)||SFB-627, B5 (University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems)|
|Entry date||September 3, 2008|