论文标题:异构数据库互访问技术研究
A Study on Transparent Access of Heterogeneous Database
论文作者
论文导师 郑秋梅,论文学位 硕士,论文专业 计算机技术
论文单位 中国石油大学,点击次数 90,论文页数 84页File Size1157K
2007-03-01论文网 http://www.lw23.com/lunwen_847324682/
Heterogeneous Database;;Data Exchange;;XML;;Digital Campus
数字化校园的主要任务之一是要整合校园内的各种应用系统,建立统一的数字校园门户,进行各个数据库相互访问,数据库间通过数据的查询、交换和共享,消灭校园网的“信息孤岛”现象。目前广泛采用的XML中间数据交换方案依赖于一个定制的XML模式,系统灵活性较差。本文采用源方和目标方数据库模式分别定义交换使用的XML模式,在两个XML模式间动态建立匹配规则,以消除数据交换的异构冲突,其优势在于实现XML模式间数据映射过程和XML模式与关系模式间转换过程的分离,避免对单一预定义XML模式的依赖。 首先对关系模式与XML模式间的转换进行研究,探索在XML模式中完整地描述数据结构、数据类型、数据约束等信息的技术途径,为关系模式与XML模式之间数据转换建立技术基础;然后对XML模式间存在的异构冲突进行分析,采用XML模式树确定源方和目标方XML模式间匹配规则;其次数据交换根据匹配规则对源XML数据进行操作生成目标XML数据。通过对匹配规则进行形式化描述,使数据交换模块独立于具体的数据转换计算,能够通过解读不同的匹配规则灵活地在XML模式间进行数据交换。最后将异构数据库交换方案应用到高校数据库系统中,采用WebServices等相关技术对该系统中的各主要模块和服务进行了详细的设计与实现,并对XML模式间的匹配和数据交换进行实验,进行了可行性验证。与单一XML模式数据交换相比,方案中各功能模块相对独立且可扩展,具有更强的通用性。
Many universities have put "Digital Campus" on their agenda. One of the major problems is to integrate all kinds of data and resources and make them accessible through campus portal. To this end, a universal data interchange platform should be built to eliminate "isolated islands of information" caused by the campus network. Data exchange could achieve data-sharing heterogeneous databases and redundantly storing the method for data exchange based on XML by eliminating conflict between data in each database. At present,is in common use. However, it is inflexible because it relies on customizing a XML schema in advance. This paper designs a dual-XML-schema solution of database exchanging to solve the problem. The source and target convert each relation schema to XML schema respectively with XML Schema Language. The heterogeneity between source and target would be eliminated by XML schema mapping with mapping rules.Since the mapping rules is created dynamically, this can adapt itself to the change occurred in source or target by updating mapping rules. dual-XML-schema solution of database exchange is applied to meet the data sharing requirement of basal universities information database. This paper also gave detailed design and implementation of the pivotal process in data exchange system, including schema conversion, schema registering, schema mapping,data exchange and so on. Finally this paper used a representative example to validate the feasibility of dual-XML-schema solution. Due to all the modules are relatively isolated and easy to extend, the solution could be used in kinds of science domain to solve data-sharing between heterogeneous databases.
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