从DTD映射到关系模式方法Hybrid Inlining的改进

Improvement on Hybrid Inlining Approach from Mapping DTD to Relational Schema

XML正迅速成为互联网上数据表示和交换的标准,用关系数据库存储XML数据是XML存储策略之一。为了将XML数据存储到关系数据库中,人们研究了很多从DTD到关系模式的映射方法。Hybrid Inlining方法是一种比较常用的映射方法,此方法将多个元素内联到一个表中,从而可以降低查询时连接操作的次数,但同时也存在一些诸如删除异常、插入异常的问题。本文将Hybrid Inlining方法运用在从Schema到关系模式的转换中,同时在Hybrid Inlining方法的基础上做进一步改进,从而解决删除、插入异常等问题。最后给出其具有无损连接性以及保持函数依赖的证明。

XML is fast emerging as the standard for representing data in World Wide Web, there are many strategies for storing XML documents and using relational database to storage XML is one kind of these strategies. In order to store the XML data in relational database, mapping DTD to relational schema is studied. Hybrid Inlining is a good approach from mapping DTD to relational schema, it inlines lots of nodes into table, it reduces the number of joining table when we query table, but Hybrid Inlining has some problems when data is deleted or inserted. This paper focuses on mapping scheme to relational schema with Hybrid Inlining, improving Hybrid Inlining so that to solve some problems such as deletion anomaly, insertion anomaly and so on. Lastly, the paper proves it is an approach to having lossless joint and Preserve Data Dependency.