中文摘要：

XML数据流上的分片策略是基于剪切的XML数据流发布系统面临的首要问题.文中针对基于剪切的XML数据流中对XML片段解析和连接的操作代价,提出了基于Hole-Filler模型的XML数据流的基本代价模型,在此基础上提出数据流自适应发布算法AXF,以期在数据和查询动态变化的情况下自动调整XML数据分片策略以获得最佳的系统运行性能、自适应能力和扩展性.实验结果表明AXF算法可以提高XML片段的有效率,在客户端、服务器及网络传输方面均获得良好的性能.

英文摘要：

The fragmentation the XML stream dissemination policy over XML stream is the first major problem confronted by system based on document fragmenting. This paper analyzes the features of the XML processing on client, network and server, and brings in the cost model for fragmented XML stream system based on Hole-Filler model. According to the cost analysis of the parsing operation and join operation over streams on clients, this paper proposes the Adaptive XML Fragmentation algorithm （AXF） on server to dynamically merge and spit the XML frag- ments with XML data and query characteristics varying constantly over time. The core algo- rithms, A-Merge and A-Split, monitor and respond to both data and query changes automatically by using online profiler as the indication to the clients＂ requirements. When XML data and query characteristics were to stabilize, AXF would lead the XML fragments converge to an optimistic fragmentation rapidly. A thorough performance evaluation presents that AXF can sacrifice some fragment validity to balance the cost between transmission amount over network and the cost of query evaluation on client. And the server can achieve 2 0 2. 5x performance improvement in scalability compared with query matching server. To the best of our knowledge, AXF is the first dynamic XML fragmenter considering merging and splitting XML fragments in an adaptive and efficient way.