基于直方图的草图技术是用于道路网的数据流聚集查询,为了说明问题，先对直方图的信息进行实例化，基于直方图的动态草图索引结构跟AMH的结构相似-we propose a dynamic sketch method by integrating sketch and histogram techniques, for aggregate queries over the network-constrained traffic data streams and build the index, to s