介绍了RealStream的运行时结构和查询处理机制，对RealStream的基础结构设计作简要的说明，介绍了窗口相关技术，提出了一种基于分级窗口的窗口维护策略。介绍了RealStream中各种窗口结构的具体设计与实现。-Introduced RealStream De Yun Hang-time structure and query processing mechanism, right RealStream the basis of the structure designed as a brief note introduces the window of the technology presented a kind of window-based classification of window maintenance. Describes the various windows RealStream specific design and implementation structure.