WEB半结构化数据查询

当前许多大的Web站点的信息和数据呈现结构化或半结构化的特点，因而可经抽象，作为类似关系数据库或面向对象数据库并加以处理，以提高操作效率，特别是在此基础上的查询操作。采用数据模型Araneus的一个子集作为数据模型，并采用连接约束、包含约束、范围约束，提出一种半结构化查询重写的方法，该方法在保证算法正确性和完备性的基础上，利用半结构化数据特点和查询子目标之间的关系，极大地降低了算法的代价。

Query semi-structured for data on web

At present, the information and data on many large web are structured or semi-structured, which can be abstracted and processed similarly as relational database or objected-oriented database to raise the operation efficiency, especially the query efficiency. The Araneus data model is used, and also the link constraint, inclusion constraint and scope constraint are used. A query rewriting for semi-structured data is put forward, and this approach greatly reduces the cost of algorithm by using the knowledge of characteristic of semi-structured data and the relation between the subgoals in the query, while the soundness and completeness of algorithm are maintained.