On Multi-way Spatial Joins with Direction Predicates

Spatial joins are fundamental in spatial databases. Over the last decade, the primary focus of research has been on joins with the predicate “region intersection.” In modern database applications involving geospatial data such as GIS, efficient evaluation of joins with other spatial predicates is yet to be fully explored. In addition, most existing join algorithms were developed for two-way joins. Traditionally, a multi-way join is treated as a sequence of two-way joins. The goal of this paper is to study evaluation of multi-way spatial joins with direction predicates: complexity bounds and efficient algorithms. We first give I/O efficient plane sweeping based algorithms for 2-way direction joins and show that by combining the plane sweeping technique with external priority search trees, a 2-way direction join of N-tuple relations can be evaluated in O(N logb N M + k) I/Os in the worst case, where M is the size of the memory, b is the page size and k is the result size. The algori...

• Type: Conference
• Year: 2001
• Where: SSD
• Authors: Hongjun Zhu, Jianwen Su, Oscar H. Ibarra
• Keywords: Database, Direction Join, Spatial Joins, SSD 2001, Star Joins