The Research Of Integration Query Technology Of Embedded Spatial Database

The traditional Embedded Geography Information System usually implements the disposal of spatial data and attribute data by the function of itself, based on the file system. However, along with the increasing application field of Embedded Geography Information System, the query requests of people become more and more complex. Such as, "query the hotel or restaurant near by a highway in 200 meter". "query the highway which covered by the floodwater flooding. It makes the resolvent of adopting embedded spatial database developed.StarSDB is an embedded spatial database system developed by our item group, which based on the open source embedded relation database SQLite. It mainly includes five parts function modules: spatial data mapping, spatial index, spatial query, query object parse and spatial data objectivization. The research of spatial data mapping and spatial index were completed. This paper mainly researches the development of spatial query, query object parse and spatial data objectivization technology, designes and implements the intergration query system of the embedded spatial database StarSDB. The key problem in this paper to settle is: how to complete the intergration query of spatial data and attribute data based on the spatial data mapping and spatial index, on the basis of query condition which inputted by users.This paper mainly researches and solves these problems:1. Expands the query function for spatial data based on the standard SQL, and implements an EGSQL language as an interface which users can query the intergration of spatial data and attribute data. It has well compatibility and expansibility.2. Aim at the system dealing with spatial data and attribute data in different order, puts forward and implements three kinds of embedded spatial database intergration query arithmetic: first attribute serial query arithmetic, first spatial serial query arithmetic and parallel query arithmetic. The test shows that the parallel query arithmetic, which adopted the POSIX multithreading programme technology under linux, has higher query efficiency and better transplantility than the others. Puts forward a suit of feasible, highly efficiency execute attemper strategy for StarSDB intergration query system.3. Designs and implements an EGSQL query analyzer. Via the analysis of syntax parse, query decompose and execute attemper, implements the veracious, highly efficiency analysis and execute of EGSQL language. It can implement the complex spatial query request inputted by users.Finally, this paper gives an application example of StarSDB intergration query system---QGIS-minus. Based on this example, we tested the performance of StarSDB intergration query system. The test result shows that StarSDB intergration query system has perfect query fuction, less memory space appropriation, quicker query response speed. It can satisfy the application of embedded GIS, which has rigorous request of memory resource and compute resource, and has well practicability and extendibility.