For example, in debugging problems where you suspect the join order is not optimal, it can be useful to gather counts for different join combinations.

比方说，在调试怀疑连接顺序不是最优的问题时，针对不同的连接组合收集计数可能会有帮助。

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For the reason of the no order of space data, the algorithm based on join index have to improve for it. The key problem of optimal page-access sequence with a fixed Buffer has been analyzed.

空间数据的无序性，使得应用在其上的利用连接索引的算法需要进一步的改进，为此分析了其中关键的最佳页访问次序问题。

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