Checking the Optimizer Mode (Oracle) 

Starting with version 7 of Oracle, two optimizer modes are available. The Optimizer session is established using the init<SID>.ora -parameter optimizer_mode .

 

 

The parameter optimizer_mode is set for R/3 Systems and should only be changed if recommended by SAP. You should also take into account the approporiate notes.

In contrast to the rule-based optimizer, you should create statistical tables for the cost-based optimizer. If you do not regularly create these table statistics, this may cause the cost-based optimizer to make wrong decisions and result in performance problems.

See also:

Displaying Oracle Table Statistics