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| Content Provider | ACM Digital Library |
|---|---|
| Author | Zhang, Donghui Tsotras, Vassilis J. |
| Abstract | We examine the problem of computing MIN/MAX aggregates over a collection of spatial objects. Each spatial object is associated with a weight (value), for example, the average temperature or rainfall over the area covered by the object. Given a query rectangle, the MIN/MAX problem computes the minimum/maximum weight among all objects intersecting the query rectangle. Traditionally such queries have been performed as range search queries. Assuming that the objects are indexed by a spatial access method, the MIN/MAX is computed as objects are retrieved. This requires effort proportional to the number of objects intersecting the query interval, which may be large. A better approach is to maintain aggregate information among the index nodes of the spatial access method; then various index paths can be eliminated during the range search. In this paper we propose four optimizations that further improve the performance of MIN/MAX queries. Our experiments show that the proposed optimizations offer drastic performance improvement over previous approaches. Moreover, as a by-product of this work we present an optimized version of the MSB-tree, an index that has been proposed for the MIN/MAX computation over 1-dimensional interval objects. |
| Starting Page | 88 |
| Ending Page | 93 |
| Page Count | 6 |
| File Format | |
| ISBN | 1581134436 |
| DOI | 10.1145/512161.512181 |
| Language | English |
| Publisher | Association for Computing Machinery (ACM) |
| Publisher Date | 2001-11-09 |
| Publisher Place | New York |
| Access Restriction | Subscribed |
| Subject Keyword | Spatial aggregates Min/max Indexing |
| Content Type | Text |
| Resource Type | Article |
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