11gR2 (11.2.0.3) : AUTOMATIC PARALLELISM

Hi ,

I tried to implement AUTOMATIC PARALLELISM (11gr2 Feature ) to run my appliaction faster but  ONLY  few queries and  DML (1%) have been executed in parallel , WHY ?

I have many queries and dml with execution time  > 10 min but they are executed in serial even when PARALLEL_DEGREE_POLICY = AUTO !

Help ...

Best regards.
GD.

SQL> sho parameter parallel
 
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
fast_start_parallel_rollback         string      LOW
parallel_adaptive_multi_user         boolean     TRUE
parallel_automatic_tuning            boolean     FALSE
parallel_degree_limit                string      16
parallel_degree_policy               string      AUTO
parallel_execution_message_size      integer     16384
parallel_force_local                 boolean     FALSE
parallel_instance_group              string