DTD Based LazyDFA Query Optimized Algorithm over XML Data Stream

A query processor called lazyDFA which is created based on the automaton technology is an effective method to solute the problem of XPath query on XML data stream.This paper proposes the optimized algorithms aimed XPath which use the semantic and structural information of DTD in order to improve the efficiency of lazyDFA.The experimental results show that optimized algorithms can effectively accelerate lazyDFA query speed, lower memory consumption.