XML数据流的特点是所有元素和值仅允许扫描1次.针对XML数据流上的聚集问题,提出了高效的XML数据流聚集算法.这种算法不但能够有效地支持XML数据流上具有复杂结构聚集查询的处理,而且能够有效地支持具有递归结构XML数据流上的聚集查询处理.理论分析和实验结果表明,算法能够有效地处理XML数据流上的聚集查询,并且具有很好的可扩展性.
Each element and value in a XML stream can be accessed only one time. In this paper, efficient algorithms are proposed for processing aggregation on XML streams. These algorithms efficiently support the processing of the aggregation queries with complex structures and the aggregation queries on XML stream with recursion structures. Theoretical analysis and experimental results show that the proposed algorithms are able to process aggregation queries effectively and efficiently on XML stream with high scalability.