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RUL

The difference between CBO and RULE

ORACLE 's optimizer has two optimization methods:Rule-Based Optimization (Rule-Based Optimization, referred to as RBO)RBO follow simple fractionation methodology, using 15 kinds level point, when receiving the query, the optimizer used to assess the number of points, and then select the best level (minimum number) to run the query execution path. Cost-Based Optimization (Cost-Based Optimization, referred to as CBO)CBO tries to find the lowest cost method to access data. For the greatest throughput or the fastest initial response time, it calculates the cost of using different execution plans

2021-05-13 19:22:51    分类:博客    cbo   RUL