【作者】 张永祥；

【导师】 王波；

【作者基本信息】 重庆大学 ， 计算机应用技术， 2011， 硕士

【摘要】 近些年来,随着计算机技术、网络技术、信息技术的高速发展以及电子产品成本的急速下降,企业的信息化得以空前的施展,信息化使得企业在发展过程中积累了不少数据。市场环境变化的复杂性以及企业发展竞争的激烈性,使得企业需要访问多种数据源的数据,以提高自身的竞争实力。由于多种原因,这些数据源之间存在异构特点,如何有效地解决这种差异性,为企业访问异构数据源提供便利,则是企业高度信息化亟待解决的问题。典型的解决方案是借助于数据库服务器,将各数据源中的数据提取出来,经过数据转换存储到中心数据库,操作中心数据库的数据,但这样会导致大量的数据重复存储,同时也影响业务的敏捷性。还有一种方案是运用数据库服务器和虚拟视图方式来到达数据集成的目的,这种方案的不足之处在于对XML数据或者非结构化数据的处理效果不佳。如何提供一个高效的、可扩展的、可靠的异构数据集成中间件,使其能够提供统一的接口为其它应用系统的开发服务,则是当前数据集成研究的热点。本文分析了当前异构数据集成领域中的主要问题,针对数据源存储结构的特点,提出数据源分类的思想,把数据源分成数据库、XML、非结构化三种类型,依据各自的特征,对每一类数据源采用统一的方式处理。对于数据库数据源,利用数据库服务器来处理;对于XML数据源,则应用XQuery引擎处理;对于非结构化数据源,转化成XML数据源来处理。利用XML模式描述数据的优点,通过提取各数据源的元数据,对元数据进行转换处理,在此基础上根据一定的规则构建虚拟数据库,使得待集成的数据源以一致的全局视图形态呈现给用户。借鉴JDBC能够访问不同数据库的设计特点,针对开发人员设计异构数据集成中间件HDAM(Heterogeneous Data Source Access Middleware),描述了中间件各功能模块的作用和运行流程,说明了HDAM的数据源注册接口和数据操作接口,研究了全局查询分解以及局部查询语句的转换算法。最后经过开发和测试验证了中间件设计方案的可行性和正确性,并通过案例演示了HDAM的应用流程。本课题基于对数据源分类的思想研究异构数据集成,提出在中间件设计中利用XQuery处理器处理XML数据,提高了中间件处理XML数据和非结构化数据的查询效率,从而使得集成中间件扩展性更好,访问速率更快。更多还原

【Abstract】 In recent years, with the rapid development of computer technology, network technology, information technology and the rapid decline in the cost of electronic product, the informatization of enterprise was implemented rapidly, in the process of informatization, companies accumulated a large amount of data. Because of the complexity of changing market conditions and fierce competition among enterprises, companies need to access multiple data sources to improve their own competitiveness. Due to various reasons, these data sources have heterogeneous features, so it is in an urgent need to effectively resolve the differences and to provide convenience for enterprises to access heterogeneous data sources.The typical solution is to extract data from each data source, convert the data format and then store data into a central database, operate the central database instead of each data source. But this solution would lead to a large amount of redundant data storage, which affects the business agility. An alternative is to integrate heterogeneous data source utilizing the database server and virtual view, however, the inadequacy is the ineffective treatment about XML data or unstructured data. How to provide an efficient, scalable and reliable heterogeneous data integration middleware which gives the uniform interface to other information systems is currently a hot spot in data integration research.This thesis analyzes the major issue on heterogeneous data integration field, and proposes the idea of classifying the data sources according to the characteristics of the data source storage structure. This solution divides data sources into three types: database, XML and unstructured data sources, and uses a uniform method to integrate each type of data source according to their characteristics: it uses database server to handle database data sources, uses XQuery processor to handle XML data sources. As for unstructured data source, it converts the unstructured data to XML data and then handle the XML data source. By taking advantages of XML schema in description of data, the metadata can be extracted and then converted, and then a virtual database according certain rules can be built to enable the data sources to be presented to users in a uniform global view. This article designed HDAM(Heterogeneous Data Source Access Middle) for developers as reference of the character of JDBC can access to different databases, described the role of each functional module and operation process, described the data source registration interface and the user interface, researched the algorithm of global query decomposition and local query conversion. At last, the middleware was developed and tested, and an application process of HDAM was demonstrated through a case. The result of test approved the feasibility and correctness of the middleware designed in the research.This subject researched heterogeneous data integration based on the idea of data source classification, proposed the idea of using XQuery processor to deal with XML data in middleware, hence improved the query efficiency of middleware when handling XML data and unstructured data, and enhanced the scalability and access rate of the integrated middleware.更多还原