Search notes:
Oracle SQL Plan operation: PX RECEIVE
The
PX RECEIVE row source always has exactly one the child which is
PX SEND.
This parent-child relationship connects two sets of parallel execution servers.
create table tq84_t (
grp number,
val varchar2(20)
) parallel;
explain plan for
select
grp,
sum(val) sum_val
from
tq84_t
group by
grp
;
select * from table(dbms_xplan.display(format => 'basic'));
--
-- ---------------------------------------------
-- | Id | Operation | Name |
-- ---------------------------------------------
-- | 0 | SELECT STATEMENT | |
-- | 1 | PX COORDINATOR | |
-- | 2 | PX SEND QC (RANDOM) | :TQ10001 |
-- | 3 | HASH GROUP BY | |
-- | 4 | PX RECEIVE | |
-- | 5 | PX SEND HASH | :TQ10000 |
-- | 6 | HASH GROUP BY | |
-- | 7 | PX BLOCK ITERATOR | |
-- | 8 | TABLE ACCESS FULL| TQ84_T |
-- ---------------------------------------------
drop table tq84_t;