Using Compact B(superscript +)-trees in Indexing Line Segments for Spatial Databases

Abstract

Points, lines, and regions are the three basic entities for constituting vector-based objects in spatial databases. Many indexing methods have been widely discussed for handling point or region data. These traditional methods can efficiently organize point or region objects in a space into a hashing or hierarchical directory. They provide efficient access methods for accurate retrievals. However, two problems may encounter when their techniques are adopted to deal with line segments. The first is that representing line segments by means of point or region objects cannot properly preserve the spatial information about line segments. The second problem is derived from the dead space and overlapping areas in external and internal nodes of the hierarchical directory caused by the use of rectangles to enclose line segments. These two problems will seriously deteriorate retrieval performance. In this paper, we propose a novel indexing structure based on a new indexing method called compact B(superscript +)-tree and this indexing structure is appropriate for use in handling line segments and remedy the suffered problems.