基于面向对象XML数据的索引机制

Indexing Mechanism for Object-oriented XML Data

XML正在迅速成为Internet上信息表示和数据交换的重要标准.而面向对象的特征具有很强的建模能力,将面向对象的概念引入到XML可以提高XML模式语言的建模能力.而现有的索引模式都不支持面向对象XML数据的查询,由此提出了一种基于面向对象XML数据的OOCtree(Object-Oriented compact tree)索引模式,它是一棵包含组级和元素级的两级双向树.组级提供简洁的结构概要和继承信息,可以在查询早期阶段裁剪大量的搜索空间;元素级提供详细的孩子父亲连接关系,可以快速地访问某元素的父亲,极大地提高了查询处理效率.

XML is emerging as the dominant standard for information exchange and data representation. Due to the strong modeling ability of object-oriented features, it is important to extend XML with object-oriented features to enhance query language modelling ability that based on XML schema. But current approaches of indexing XML data＇s structures don＇t support indexing object-oriented XML data, so an OOCtree （Object-Oriented compact tree） indexing model is proposed that based on objectoriented XML data, it is a two-level tree including group level and element level. Its group level provides concise structure summary that may prune a large searching space at the early stage of query processing ： its element level provides detailed childparent relationships and inherence information that may fast access to elements＇ father and greatly enhance query processing efficiency.