The Design And Implementation Of Data Stream Query Algrorithm Based On XML

With the rapid popularization of Internet,the proportion of network in people's lives is also growing. There have been a large number of applications about XML data stream,such as blogs, stock analysis, network monitoring data security management, location information and electronic information search.Data transmitted in the form of XML data stream have the following characteristics:data volume is huge and unpredictable;all the data is arriving online,we don't know the order of their arrival. Clearly, the traditional way of dealing with DataBase management will be very difficult and cause a lot of waste, because the data in traditional DataBase management are all predictable and storable.In recent years, researchers have proposed a variety of algorithms for XML data stream query, such as TurboXPath and StreamTX algorithms. But TurboXPath has been shown that it have a potential hazard in the recursive call. StreamTX algorithm will cause a very high cost when dealing with queries include Parent-Child (PC) relation.All these algorithms are unable to present a satisfactory performance in efficiency and flexibility.So we need to design a more effective search algorithms.To solve these problems, A twig matching algorithm called TwigPM was presented. For XML data stream may have a complex recursive,hierarchical structure. TwigPM carried out an effective pruning algorithm, It Reduces the processing time and memory storage space for storing data by obtaining the structure of relationships among Query node. Algorithm functions are divided into two parts.The first part gets the structure of these nodes in query tree, including the parent-child relationship and ancestor-descendant relationship, these different nodes were classified into different parts.The second part is the pruning and the matching process.To deal with these event arrives in order,it removes these nodes that will never exist in the final answer with using pruning operation.It also gets the result by using matching operation when there comes the EE element of query tree.At last, we did many performance test for our algorithm.Experimental results show that TwigPM is efficient, especially in dealing with these queries include Parent-Child(PC) relation. TwigPM can avoid the independent match and makes the efficiency higher.