In the field of distributed database , the distributed deposition and redundancy of the data bring convenience to resume from the break - down system , but make the distributed query processing become more complicated , so how to query data quickly and accurately what customer wants have become an important problem in distributed database system 摘要分布式数据库中,数据的分散存放和冗余给故障恢复带来了方便,同时也使得分布式查询处理变得更加复杂,因此如何快速准确的查询用户想要的数据成了分布式数据库系统中的一个重要问题。