alter system set result_cache_mode=manual;

alter system set result_cache_max_size=;

alter system set "_optimizer_ads_use_result_cache"=false;

alter system set "_column_tracking_level" = scope=both;

alter system set "_optimizer_enable_extended_stats" = false;

alter system set  "_optimizer_dsdir_usage_control" = ;

alter system set OPTIMIZER_ADAPTIVE_FEATURES=false;

alter system set "_fix_control"='17376322:OFF';

Alter system set "_cursor_obsolete_threshold"= scope=spfile;

modify initora12c.ora

sga and pga

startup pfile= ..../initora12c.ora

create spfile from pfile

shutdown and startup

modify parameter

alter system set db_cache_size=xxxx scope=spfile

alter system set shared_pool_size = xxxx scope=spfile

alter system set inmemory_size=xxxx scope=spfile

alter system set inmemory_max_populate_servers=xxxx scope=spfile

shutdown and startup

alter tablespace xxxxx default inmemory