add/drop policy

begin dbms_rls.add_policy(object_schema => 'xxx',object_name => 'xxx',policy_name => 'xxx',policy_function => 'xxx.xxx',function_schema=>'xxx'); end;
/

begin dbms_rls.drop_policy(object_schema => 'xxx',object_name => 'xxx',policy_name => 'xxx'); end;
/