一种XML数据库上谓词“Contain”的实现方法

TOWARDS SUPPORTING CONTAINMENT-OPERATOR ON XML DATABASE

路径表达式查询是XML数据查询处理的核心研究问题之一,研究者开展了大量的研究工作。但这些研究更多关注XML数据上路径表达式的匹配,忽略了谓词"包含"。研究XML查询处理中谓词"包含"的查询处理方法。采用了两种方法,第一种是采用跳跃表的方法,在XML分枝模式匹配时动态地对结点数据进行读取和关键字匹配。第二种是为XML文档中的词语建立倒排索引,来实现关键字的匹配。并从分枝模式路径长度、查询关键的数量和"包含"谓词判断结点的类型,对两种方法进行了分析和比较。

Path-Expression-Query processing,which is one of the core problems in XML data management studies ,has received lots of attentions recently. Much works have focused on path expression matching in XML database. These works, however, neglect the containment operator. We studied the implements of the containment operator on XML database in this paper and proposed two methods. The first one uses jump table for carrying out the dynamic search of node data and matching keywords in twig pattern matching query of XML,while the second one sets up inverted indices for terms in XML documents to implement keywords matching. We compared and analyzed two methods with the length of the path of twig pattern, the amount of keywords queried and the type of the judgement nodes with containment operator in XLM tree.