On 08/16/2016 05:54 PM, Jonathan Lewis wrote:
You get dynamic sampling in 12c as the third level response to adaptive execution plans.
First you get a plan, then you get a new plan using statistics feedback, then you get an SQL Plan Directive generated because of the in-memory statistics feedback (visible in v$sql_reoptimization_hints), and the directive(s) generally tells Oracle to do dymamic sampling.
Check dba_sql_plan_directives to see how many you've got.
You may find you have to disable the adaptive feature and delete all the directives - the latter through the dbms_spd package.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
@jloracle
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