Research On Serveral Critical Technologoes Of Spatial Database Engine

Spatial database engine contacts spatial database system with GIS application. It abstracts spatial data and spatial operation. The spatial database engine needn't take the differences between all spatial database systems into account, so the client program needn't care about the store format of the spatial data and the methods of spatial operation.This paper focuses on the key technologies of spatial database Engine, e.g. the spatial index,the editing of spatial data, and gives a new solution method. Following contents are included in this paper: (1) The research on spatial data store model. It describes several popular format of spatial data store. (2) The comparison between some spatial indexes. It compares R-tree index with Quadtree index. R-tree index is flexiable and well-knit with database, but it costs much time when insert and delete. Quadtree index is simple and convenient to inserting and deleting, takes less memory, but it's hard to expend. This paper gives a new index which combine linearly sortable Quadtree and object region query. This index has good expansibility and improved query precision. (3) This paper gives a new spatial data editing method, assistant table method. Also it improves single-record locking method, gives a time limitation of committing the editing result. It resovles the current problem in spatial data editing, keeps the coherence of data, and turns data sharing and effective roll-back into realization.