空间数据访问集成与分布式空间数据源对象查询

Access and Integration on Geospatial Data and its Distributed Query

目前,针对空间数据库的访问与处理方法,无法满足分布式环境下异构数据源的服务化存取和面向空间数据源的对象查询处理需求。本文给出了数据网格环境下的分布式空间数据访问与查询的方法和实现,并在服务化查询处理过程中,嵌入符合SQL/MM查询规范的空间拓展函数,实现分布式空间数据对象查询和嵌入查询过程中的空间数据分析处理。在此基础上,给出空间数据对象查询树的构造过程,以及分布式空间查询工作流的执行流程。数据访问与集成策略在空间数据处理上的应用,对异构空间数据源协同处理等,涉及大规模空间数据存取访问的应用需求,有很好的理论和实际应用价值。

Integration of distributed spatial data source is critical in geospatial data storage and analysis.In the solution of data grid architecture,data service is introduced to integrate different heterogeneous resource.Access and integration of data service is the key method to build the infrastructure of data sharing and integration.In data grid infrastructure,OGSA-DAI middleware provides uniform access to distributed heterogeneous databases and allows queries to be run over these as if they were a single database.Different from the database connection layer between clients and data,DAI provides server-side data workflow engine designed for data integration,federation and distributed query support across multiple types of database and file system.In this paper,we propose the data grid architecture for geospatial data sharing and integration,which is based on grid service container and data grid middleware.Based on the proposed architecture,we provide the data grid based method for spatial data access and integration via data service with the heterogeneous database communication platform.Besides,we introduce distributed query processing（DQP） system to provide high level data integration solution for service-based grids as well as supporting distributed resources query and accessing.In addition,this paper explores combining distributed object query language and geospatial query functions for spatial data sharing and integration on top of data grid component.Object query tree is also provided to illustrate the analysis and execution of query sentence in accordance with SQL Multimedia specification.SQL/MM Spatial is mainstream international standards for spatial database access and query.By combining the distributed object query and geospatial query,we hope to have leverage with strengths in both of them.The approach of spatial data access and integration,as well as the description,deployment and invoking of data services in distributed environment will contribute a lot for the storage and continuous integration of geological survey and remote sensing data.