Setting OPTIMIZER_ADAPTIVE_FEATURES in Oracle Database 12c Release 2
In Oracle Database 12c Release 2 the parameter OPTIMIZER_ADAPTIVE_FEATURES was declared “Obsolete”. It was replaced by the parameters optimizer_adaptive_statistics, optimizer_adaptive_plans and AUTO_STAT_EXTENSIONS to allow better control of the adaptive features of the optimizer but what happens, if you try the set OPTIMIZER_ADAPTIVE_FEATURES on a 12.2 database?