Modified Single-Link Management Method for Spatial Query Optimization in Spatial DBMS

W. Chung (Korea), J. Li (PRC), K.-C. Jung, S. -J. Lee, and H.-Y. Bae (Korea)

Keywords

Spatial DBMS, Query Optimization, Spatial Query

Abstract

Generally, the single-link method, double-link method and none-link method are used to manage the spatial data, but there are some shortcomings. The single-link method limits the efficiency of spatial processing. In the double link method, maintaining the forward link and backward link is a tiresome work; more even, many efficient query strategies cannot be used directly or cannot be used at all. In the none-link method, every time a tuple participates in a join, the full description of spatial object needs to be duplicated as well. In addition, the data redundancy is a serious problem in the spatial database, especially the query produced by computer contains redundant derived tables, the Cartesian product is used as the general solution method, and thus the performance is very low. In this paper, we propose a modified single-link management method to manage varied spatial data because of the simplicity of the single-link management method. When the spatial part and aspatial part's total size is small than the page size, we store them together in one page, or, we store the aspatial part and some necessary information together in one page while storing the spatial object in the BLOB. The proposed methods are implemented in our spatial query processor. The evaluation results show that the modified single-link management methods achieved better performance than the conventioinal single-link management method.

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