%0 Journal Article
%T Querying and Optimizing Semistructured Data<br>半结构化数据查询的处理和优化
%A CHEN Ying
%A WANG Neng-bin
%A <br>陈滢
%A 王能斌
%J 软件学报
%D 1999
%I 
%X Semistructured data has irregular or incomplete structure. In recent research on semistructured data sources and integration for heterogeneous data sources, models for semistructured data are based on direct graph with root vertex, so querying semistructured data is equivalent with searching in graph. In addition, path with wildcard characters brings more complexity in query processing. In this paper, the authors present the strategies deployed in querying and optimizing OIM (model for object integrating) data in Versatile-a system for integrating heterogeneous data sources. Algorithms for generating query plan and extending path are dis-cussed in detail and three optimization methods, path index (Pindex), level index(Lvindex) and knowledge of data source are introduced. Also the approach can be applicable to other graph-based semistructured data easily.
%K Semistructured data
%K query processing
%K optimization<br>半结构化数据
%K 查询处理
%K 优化.
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=8240383F08CE46C8B05036380D75B607&jid=7735F413D429542E610B3D6AC0D5EC59&aid=B00CE9DB647B8B0E&yid=B914830F5B1D1078&vid=F3090AE9B60B7ED1&iid=5D311CA918CA9A03&sid=899CC9158FC43EF4&eid=38DB5AF4AD8FDCCA&journal_id=1000-9825&journal_name=软件学报&referenced_num=9&reference_num=14