Incremental Distance Join Algorithms for Spatial Databases

Two new spatial join operations, distance join and distance semijoin, are introduced where the join output is ordered by the distance betweenthe spatialattribute values ofthe joined tuples. Incremental algorithms are presented for computing these operations, which can be usedin a pipelined fashion, thereby obviating the needto wait for their completion when only a few tuples are needed. The algorithms can be used with a large class of hierarchical spatial data structures and arbitrary spatial data types in any dimensions. In addition, any distance metric may be employed. A performance study using Rtrees shows that the incremental algorithms outperform non-incremental approaches by an order of magnitude if only a small part of the result is needed, while the penalty, if any, for the incremental processing is modest if the entire join result is required.

• Type: Conference
• Year: 1998
• Where: SIGMOD
• Authors: Gísli R. Hjaltason, Hanan Samet
• Keywords: Database, Distance Betweenthe Spatialattribute, Incremental Algorithms, SIGMOD 1998, Spatial Join Operations