optimizer level

optimizer level determines the level of optimization the query processor uses.

Summary Information
Default value	ase_default
Range of values	ase_current – enables all optimizer changes through the current release. ase_default – disables all optimizer changes since version 1503 ESD #1. ase1503esd2– enables all optimizer changes through version 15.0.3 ESD #2. ase1503esd3 – enables all optimizer changes through version 15.0.3 ESD #3.
Status	Dynamic
Display level
Required role	System administrator
Configuration group	Query Tuning

The values for optimizer level are character data, so you must use 0 as a placeholder for the second parameter, which must be numeric.

See Performance and Tuning Series: Query Processing and Abstract Plans > Controlling Optimization for information about optimization levels.