Search notes:

Oracle hints: ENABLE_PARALLEL_DML, DISABLE_PARALLEL_DML

Preparation of tables:

create table tq84_src as select * from dba_objects;
 
create table tq84_dest (
   id   number,
   own  varchar2(128),
   nam  varchar2(128),
   typ  varchar2( 20)
);

The following (explained) SQL statement uses the parallel hint.

explain plan for
insert /*+ parallel(4) */ into tq84_dest
select
   object_id,
   owner,
   object_name,
   object_type
from
   tq84_src;

The statement's execution plan places the LOAD TABLE CONVENTIONAL operator «above» the PX COORDINATOR operator which indicates that tq84_dest is not filled in parallel (although the data from tq84_src is selected in parallel).

The plan also has the PDML is disabled in current session note which confirms this observation:

select * from dbms_xplan.display(format => 'basic +note');
--
-- ----------------------------------------------
-- | Id  | Operation                | Name      |
-- ----------------------------------------------
-- |   0 | INSERT STATEMENT         |           |
-- |   1 |  LOAD TABLE CONVENTIONAL | TQ84_DEST |
-- |   2 |   PX COORDINATOR         |           |
-- |   3 |    PX SEND QC (RANDOM)   | :TQ10000  |
-- |   4 |     PX BLOCK ITERATOR    |           |
-- |   5 |      TABLE ACCESS FULL   | TQ84_SRC  |
-- ----------------------------------------------
-- Note
-- -----
--    - Degree of Parallelism is 4 because of hint
--    - PDML is disabled in current session

The enable_parallal_dml hint is added:

explain plan for
insert /*+ enable_parallel_dml parallel(4) */ into tq84_dest
select
   object_id,
   owner,
   object_name,
   object_type
from
   tq84_src;

This changes the execution plan such that tq84_dest is filed in parallel (the development/databases/Oracle/SQL/statement/execution/plan/operations/load/as-select/hybrid-tsm-hwmb operator is now found «below» the PX COORDINATOR operator).

In addition, the PDML is disabled in current session note is now gone:

select * from dbms_xplan.display(format => 'basic +note');
-- 
-- --------------------------------------------------------
-- | Id  | Operation                          | Name      |
-- --------------------------------------------------------
-- |   0 | INSERT STATEMENT                   |           |
-- |   1 |  PX COORDINATOR                    |           |
-- |   2 |   PX SEND QC (RANDOM)              | :TQ10000  |
-- |   3 |    LOAD AS SELECT (HYBRID TSM/HWMB)| TQ84_DEST |
-- |   4 |     OPTIMIZER STATISTICS GATHERING |           |
-- |   5 |      PX BLOCK ITERATOR             |           |
-- |   6 |       TABLE ACCESS FULL            | TQ84_SRC  |
-- --------------------------------------------------------
-- Note
-- -----
--    - Degree of Parallelism is 4 because of hint

drop table tq84_src;
drop table tq84_dest;

Oracle hints: ENABLE_PARALLEL_DML, DISABLE_PARALLEL_DML

See also