基于数据网格面向服务的查询算法

面向服务的框架（SOA）为用户的服务提供了一个标准的平台，实现服务的提供、发现、配置和集成，以帮助用户查询和处理信息．数据网格是面向服务的架构，为用户进行分布式远程数据查询服务提供了保障．对网格环境下Hidden Web数据库的研究与开发逐渐成为人们关注的焦点问题．要回答用户的查询，数据集成系统需要解决网格上的需求语义分析和关键字查询、建立数据查询模型．将数据库抽象为无向图，节点对应数据库中的元组，边对应“主-外码”的关系．查询的结果是与元组连接的答案树，它与查询的关键字相匹配．针对以上这些问题提出了一个新的查询算法，将改进的动态规划算法用于查询模型，保证Top-1答案树最优，Top-K答案树近似最优；给出了实验测试和评估结果．

Service-Oriented Search Algorithm on Data Grid

A service-oriented architecture provides a standards-based platform that allows services to be provided, discovered, configured and integrated, to facilitate the creation of a business process. Data Grid is a service-oriented architecture that provides the coordinated search services for data distributed across remote resources. Research and development activities relating to the Grid have generally focused on application where data is stored in database which is called Hidden Web. To answer user queries, a data integration system employs a set of request semantic analyzing, keywords searching and model creating on Grid. This paper presents a novel model of searching, which the database is an undirected graph, of which each node correspond to a tuple of the database, and each edge correspond to a "primary key-foreign key" link. Results to a query are modeled as answer trees connecting tuples that match individual keywords in the query. This paper also presents a novel and efficient searching algorithm of dynamic programming, and the algorithm is employed in authors model to ensure the Top-1 answer tree optimal and Top-K answer trees nearly optimal. Finally, the algorithm's performance is tested and evaluated.