Key Technology Research Of Spatial Database Based On MySQL

Spatial database uses relational database to manage the spatial data, including the geographic and attribute data. It provides effective storage, query and analysis to the applications which are based on these spatial data. Currently, there are two spatial database modes:one is the parasitic mode which used the relational database plus the spatial data engine, the other is the integration mode which used the relational database to support the spatial data. The parasitic mode uses the middleware technology, and the integration mode uses the database technology. This article studies the spatial database based on MySQL, which is also belong to integration mode.MySQL is a small relational database management system, which joins the spatial module to achieve the OpenGIS prescribed geometric data types after version4.0, as well as some simple spatial data operation. But MySQL Spatial has not been updated and enhanced, and the spatial extension function supported by MySQL is still not strong. Currently, there are lots of algorithms for spatial data analysis and calculation. Therefore, it will be a very significant thing to add more efficient spatial data analysis and calculation algorithms to MySQL, so as to strengthen and improve the MySQL Spatial features.This article first introduces some basic knowledge about spatial database, MySQL, MySQL Spatial, and also describes some concept about spatial data analysis and calculation. Then, under the reference of Alan Murta’s GPC library, elaborated on the idea and implementation of the polygon overlay algorithm proposed by Vatti, write a MFC program to test the improved GPC library, which proved that the improved GPC library works correctly. Later, research how to compile the MySQL source code, and explore three methods of adding SQL function to MySQL, choose MySQL native function as the method to expand MySQL Spatial features after the comparison of above three different methods. Finally, Study how MySQL is designed as a spatial database by analysis its source code, mainly focused on how is the spatial data stored, quiried and computed in MySQL Spatial. Then on this basis, try to add the polygon overlay operation into MySQL, after a series of test with the MySQL client, the result show that MySQL server has successfully supported the polygon overlay operation, which also proved that the method of MySQL native function is suitable for expanding MySQL Spatial features.