一种基于XQuery的查询分解算法

A Query Decomposition Algorithm Based on XQuery

针对查询分解算法查询的局限性和较低的查全率,提出了一种基于本体XQuery语言FWR表达式的查询分解算法.该算法利用XQuery全局查询语句,以FWR表达式的3项操作(构造查询范围、子查询条件和子查询输出属性集)将基于全局本体的查询分解到针对局部本体的子查询,能够降低查询分解的复杂性、保证查询的语义完整性,并能提高查全率.通过实例进行具体分析,验证了算法的有效性.

According to the limitation and low recall ratio of query decomposition algorithm, this paper puts forward a query decomposition based on FWR expression of ontology XQuery lan-guage. Using XQuery global query language, this algorithm decomposes query based on global ontology into sub-queries for local ontology with 3 operations of FWR expression （construct que- ry range, query condition and output attribute set of sub--query）. It can decrease the complexity of query decomposition, ensure semantic integrity of query and increase recall ratio. Through concrete analysis with examples, we verify the validity of XQuery algorithm.