分布式综合查询调度技术研究

【作者】 刘宇；

【导师】 彭甫阳； 王怀民；

【作者基本信息】 国防科学技术大学 ， 计算机科学与技术， 2002， 硕士

【摘要】 查询调度问题是分布式开放环境中进行查询处理的一个关键问题。给定一个用户的查询，假定我们已经知道有n个资源与应答这个查询相关，则我们需要解决的首要问题就是考虑我们应当如何将查询分解为n个子查询，每个子查询对应一个单一的资源。其次是在存在站点之间的连接时如何为n个子查询实现同步。第三是如何根据用户的原始查询表达式将从n个信息源上返回的结果打包并装配起来。 经过研究和探索，我们实现了一个分布式综合查询调合系统(Distributed Integration Mediation System)，我们在这个环境中解决了前面两个问题。本文的主要内容包括： 1．DIMS系统介绍； 2．元数据模式(接口描述语言和接口查询语言)； 3．分布式综合查询调度框架； 4．分布式综合查询调度和优化技术研究。更多还原

【Abstract】 One of the key issues for query processing in distributed open environments is the query scheduling problem. Given a user query, after we know that there are n sources that are relevant to the answer of this query, the first issue we need to address is how to decompose the query into n subqueries, each targeting at one single source. The second issue is how to synchronize these n subqueries in the presence of inter-site joins. The third issue is how to package and assemble the results from n information sources according to the original query posed by the user.We have done a series of research of the question ,and have achieved Distributed Integration Mediation System (DIMS). We have resolved the first two questions in the context of DIMS. This thesis includes the following contents:1. Introduction of DIMS.2. Researching of metadata model (DIMS-IDL/IQL).3. Researching of distributed interoperable query scheduling framework.4. Researching of distributed interoperable query scheduling and optimizing technology.更多还原