Ludwig-Maximilians-Universität München, Institut für Informatik
Technical Report 93-04
- TITLE:
-
Approximation-based Query Processing in Spatial Database Systems
- DATE:
-
March 1993
- AUTHORS:
- Thomas Brinkhoff
<brink@informatik.uni-muenchen.de>
- Hans-Peter Kriegel
<kriegel@informatik.uni-muenchen.de>
- Ralf Schneider
- Institut für Informatik
- Universität München
- Leopoldstr. 11B
- D-80802 München (Germany)
- KEYWORDS:
-
spatial database systems, spatial objects, point queries,
spatial query processing, spatial access methods, object approximations,
conservative approximations, convex approximations, R-Tree, R*-tree
- ABSTRACT:
-
The management of geometric objects is a prime example of an application where efficiency is the bottleneck; this bottleneck cannot be eliminated without using suitable access structures. The most popular
approach for handling complex spatial objects in spatial access methods is to use their minimum bounding boxes as a geometric key. Obviously, the rough approximation by bounding boxes provides a fast but
inaccurate filter for the set of answers to a query. In order to speed up
the query processing by a better approximation quality, we investigate
six different types of approximations. Depending on the complexity of
the objects and the type of queries, the approximations 5-corner, ellipse
and rotated bounding box clearly outperform the bounding box. An important ingredient of our approach is to organize these approximations
in efficient spatial access methods originally designed for bounding
boxes.
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Robert Stabl
(28.11.1994)