Performance Evaluation of Spatial Join Strategies

Abstract

Spatial database users frequently need to combine two spatial inputs based on some spatial relationship between the objects in the two inputs, for example, map overlap. This operation of combing two inputs based on their spatial relationship is called a spatial join, which is an expensive operation. Rotem’s algorithm is a well-known approach for overlap detection, which is based on a new join index. However, there are some errors in Rotem’s algorithm, which can result in some wrong answers. Brinkhoff et al. have proposed a different approach for overlap detection which is based on the R-tree. In this paper, we first correct the errors in Rotem’s algorithm. Next, we study the performance of Rotem’s and Brinkhoff et al/’s algorithm needs longer join processing time, a larger number of comparisons and a smaller number of buffers than Rotem’s algorithm