Check on consistency of tree pattern queries under DTD constraints
DTD约束下的树模式查询的一致性判断

Tree pattern queries have been widely used in querying XML data. The check on consistence of tree pattern queries can avoid unnecessary calculation, save query processing time, and improve query efficiency. The definition of query consistency was given. Based on the concept of sub-path, an algorithm for checking consistency of tree pattern queries was proposed in presence of Document Type Definition (DTD). The analysis and comparison show that the algorithm is effective.