The Efficient Query Evaluation Plan in the Spatial Database Engine

A new GIS software Spatial Database Engine (SDE) has been developed to integrated with spatial database that combines conventional and spatially related data. As we known well in the traditional relation database system, the query evaluation techniques arc a well-researched subject, many useful and efficient algorithms have been proposed; but in the spatial database system, it is a litter difference with the traditional ones. Based on the Query Graph Model (QGM), we implemented our own query evaluation plan in thc SDE, which can deal with the full functionality query statement SELECT-FROM-WHERE-GROUPBY-HAVING, and treat the spatial data and non-spatial data seamlessly. We proposed a novel multi way join algorithm base on nest loop that may be attractive.