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[摘要]
本文对半连接运算进行扩展,提出一个新的循环查询求解方法——标志位映射法,该方法能将循环查询中的所有关系完全化简,代价为5n—4次相邻结点间的数据传输,其中n为查询图中的结点数。
[Key word]
[Abstract]
The semi-join relational operation is augmented and a new method for solving cyclic queries in distributed databases is described in the paper. This new method can fully reduce all the relations in a cyclic query. 5n-4 times of data transmission is required to carry out this new method, where n stands for the number of nodes in the query graph.
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[基金项目]
