分布式数据库中重复查询的半连接算法研究
The research of semi-join algorithm in distributed database duplicate query
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摘要: 分布式数据库系统中查询优化处理是非常重要的一环.在分析了基于半连接查询优化算法的同时,结合分布式数据库应用中存在的大量的重复查询操作的特点,提出了一种基于重复查询的半连接算法,利用存储少量的中间结果,从而缩短了计算时间和传输时间,提高了查询效率.Abstract: The query optimization plays important roles in distributed database system.After analyzing algorithm which based on semi-join query,and combining the character of distribute database that there are lots of duplicate queries.It is put forward a kind of semi-join algorithm based on duplicate query.Using a small intermediate result set to reduce the time of calculation and transmission,improved the efficiency of query.