Performance Tuning Optimizer mode. It will collect the statistics of the object. Optimizer will 1.transform the query – parsed 2.estimate 3. Generate a plan. Rule based optimizer (RBO) – deprecated from 10g onwards. Cost based optimizer (CBO) Keyword RBO – Rule. 15 objects can be gathered. CBO – Choose (or) All_rows, First_rows & first_rows_n. More than 256 objects can be gathered. The cost based optimizer will always select the low cost. It may be an index scan or table scan, which is lower. Parameters Choose / All_rows – It will gather the stats for all the rows of the table. First_rows – Only first row of the table First_rows_n –…