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• 关于Hash Joins

  2004-06-17 16:04:22   /   Oracle数据库管理

  谁能详细解释一下HASH JOIN的过程.我曾看到如下资料,但不是甚解Hash joins are used for joining large data sets. The optimizer uses the smaller of twotables or data sources to build a hash table on the join key in memory. It then scansthe larger table, probing the hash table to find the joined rows.This method is best used when the smaller table fits in available memory. The cost isthen limited to a single read pass over the data for the two tables.However, if the hash table grows to

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