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Spatial joins are one of the most important operations for combining spatial objects of several relations. The efficient processing of a spatial join is extremely important since its execution time is superlinear in the number of spatial objects of the participating relations, and this number of objects may be very high. In this paper, we present a first(More)
Spatial joins are one of the most important operations for combining spatial objects of several relations. In this paper, spatial join processing is studied in detail for extended spatial objects in two-dimensional data space. We present an approach for spatial join processing that is based on three steps. First, a spatial join is performed on the minimum(More)
In this paper, we show that spatial joins are very suitable to be processed on a parallel hardware platform. The parallel system is equipped with a so-called shared virtual memory which is well-suited for the design and implementation of parallel spatial join algorithms. We start with an algorithm that consists of three phases: task creation, task(More)
Global clustering has rarely been investigated in the area of spatial dambase systems although dramatic performance improvements can be achieved by using suitable techniques. In this paper , we propose a simple approach to global clustering called cluster organization. We will demonstrate that this cluster organization leads to considerable performance(More)
The basic concept for processing spatial joins consists of two steps: First, the spatial join is performed on the minimum bounding rectangles of the objects by using a spatial access method. This step provides a set of candidates which consists of answers (hits) and non-answers (false hits). In the second step, the exact geometry of the candidates is(More)
Comments: Minimum Bounding Boxes are often used in algorithms as a heuristic to improve the runtime. A Minimum Bounding Box is a closed volume containing the set of the unions of its contents. It is often used to eliminate, with a large amount of error, chunks of the data from being considered in an intersection. Sources: • Barequet and Har-Peled,(More)
Due to the high complexity of objects and queries and also due to extremely large data volumes, geographic database systems impose stringent requirements on their storage and access architecture with respect to efficient query processing. Performance improving concepts such as spatial storage and access structures, approximations, object decompositions and(More)