面向无线传感器网络多连接的数据卸载策略

Load shedding strategies for multi-join in wireless sensor networks

定义了局部规划卸载模式和全局规划卸载模式,分别针对两种卸载模式提出两种卸载策略:局部关联卸载策略和全局关联卸载策略.局部关联卸载策略改进了已有的独立卸载策略,按照某个顺序进行关系上的卸载计算,考虑了关系之间的卸载影响,因而可以比独立卸载策略保留更多的结果.全局关联卸载策略将所有参与连接的关系元组进行全局考虑,从中选择被卸载的数据元组.针对局部关联卸载策略提出两种改进算法:大损失优先关联卸载和多轮关联卸载算法.实验说明提出的数据卸载方法比已有的方法产生更大的卸载后连接结果集.

We define two shedding modes,the local shedding mode and the global shedding mode,for which two shedding strategies,the local associated shedding strategy and the global associated shedding strategy,are proposed,respectively.The local associated shedding strategy improves existing independent load shedding strategy,and considers load shedding over relations in an ordered and associated manner,thus can preserve more results than independent shedding strategy.The global associated shedding strategy considers tuples from all involving relations globally,and chooses evicted tuples from this global view.Max-loss-first associated shedding and multi-cycle associated shedding algorithms are also presented for improving local associated shedding strategy.Experimental results show that proposed approaches can produce more join results than existing approach.