Methods for XML phrase query processing over a collection of XML documents

Techniques to evaluate XML queries with multiple keywords having fixed relations, such as conjunction, disjunction, ancestor-descendant, and preceding-following, have already been developed. However, an English phrase with a large number of keywords cannot be mapped only with the above keyword relations. A new method to evaluate such natural phrase as the query over a collection of XML documents is necessary. As per our knowledge, such method to evaluate natural phrases in multiple XML documents does not exist. In this paper, we propose a new method to evaluate phrase queries. The inverted file structure and the query processing algorithms have been modified for this purpose. Our prototype implementation of XML query processing has demonstrated that our method can effectively evaluate phrase queries.