Question on explain plan.
- From: "Paresh Patel" <paresh.patel@xxxxxxxxxxxxxx>
- To: "oracle-l" <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 3 Jun 2009 17:44:54 -0700
Folks,
Below is an explain plan of SQL which uses parallelism for both tables
T_A and T_B , I would like to know what are the full form of PCWP and
PCWC in IN-OUT column and how are those different than P-> P?
------------------------------------------------------------------------
------------------------------------------------------------
| Id | Operation | Name
| Rows | Bytes | Cost (%CPU)| Time | TQ |IN-OUT| PQ Distrib |
------------------------------------------------------------------------
------------------------------------------------------------
| 0 | INSERT STATEMENT |
| 1637K| 171M| 371K (57)| 00:00:33 | | | |
| 1 | PX COORDINATOR |
| | | | |
| | |
| 2 | PX SEND QC (RANDOM) | :TQ10003 |
1637K| 171M| 371K (57)| 00:00:33 | Q1,03 | P->S | QC (RAND) |
| 3 | HASH GROUP BY |
| 1637K| 171M| 371K (57)| 00:00:33 | Q1,03 | PCWP | |
| 4 | PX RECEIVE |
| 1637K| 171M| 371K (57)| 00:00:33 | Q1,03 | PCWP | |
| 5 | PX SEND HASH | :TQ10002
| 1637K| 171M| 371K (57)| 00:00:33 | Q1,02 | P->P | HASH |
| 6 | HASH GROUP BY |
| 1637K| 171M| 371K (57)| 00:00:33 | Q1,02 | PCWP | |
|* 7 | HASH JOIN |
| 1637K| 171M| 365K (56)| 00:00:32 | Q1,02 | PCWP | |
| 8 | PX RECEIVE |
| 1637K| 101M| 4172 (46)| 00:00:01 | Q1,02 | PCWP | |
| 9 | PX SEND HASH | :TQ10000
| 1637K| 101M| 4172 (46)| 00:00:01 | Q1,00 | P->P | HASH |
| 10 | PX BLOCK ITERATOR |
| 1637K| 101M| 4172 (46)| 00:00:01 | Q1,00 | PCWC | |
| 11 | TABLE ACCESS FULL| T_A
| 1637K| 101M| 4172 (46)| 00:00:01 | Q1,00 | PCWP | |
| 12 | PX RECEIVE |
| 165M| 7120M| 300K (47)| 00:00:27 | Q1,02 | PCWP | |
| 13 | PX SEND HASH | :TQ10001
| 165M| 7120M| 300K (47)| 00:00:27 | Q1,01 | P->P | HASH |
| 14 | PX BLOCK ITERATOR |
| 165M| 7120M| 300K (47)| 00:00:27 | Q1,01 | PCWC | |
| 15 | TABLE ACCESS FULL| T_B
| 165M| 7120M| 300K (47)| 00:00:27 | Q1,01 | PCWP | |
------------------------------------------------------------------------
------------------------------------------------------------
F Y I: I used to dbms_xplan.display to get this explain plan....
Thanks in advance.
Paresh~
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