数据库复制是保持数据一致性、提高灾难应对能力和数据可访问性的途径。目前常用的复制工具大多采用异步方式，需要处理增量的问题。本文在Daffodil Replicator的基础上，针对数据库净增量复制技术做一些探讨和研究，提出利用窗口算法来平衡产生、传输和解析净增量数据的资源压力和时间代价，对该算法的时间复杂度做出估计，使用采样的方法来拟合时间函数曲线，确定最优情况。

Database replication is usually used to keep data consistency and enhance disaster tolerance and data accessibility. A majority of replication tools are asynchronous, which always face increment replication problems. In this paper, based on the tool named “Daffodil Replicator”, a “windowbased net increment replication” algorithm is used to balance the resource pressure and the time cost when the program generates, delivers and parses net increment data. To optimize this algorithm, sampling is used to analyze the best parameters for the timecost function.