Query optimization based on complicated scheme indexes
Nanhai Yang · Jisuanji yingyong yanjiu · 2007
The paper analyzed XML query and the relationship between XML scheme and XML documents.Proposed a complicated scheme index-based XML query optimization method.Indexed parent/child node and ancestor/descendant node,took the XML scheme with loop into account.Firstly pretreated the query tree with repetitive labels,then decomposed the query tree into main path and branch path.When executed the query,applied the indexes to accelerate the query calculation.This method would reduce greatly number of join,improve the efficiency of query.It could process the complicated scheme.The result of the experiments indicate that the performance of this method is excellent.