SQL> set autotrace on explain
SQL> select * from dual;
D
-
X
Plan d'exécution
----------------------------------------------------------
Plan hash value: 272002086
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 2 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS FULL| DUAL | 1 | 2 | 2 (0)| 00:00:01 |
--------------------------------------------------------------------------
SQL> select /*+ PARALLEL */ * from dual;
D
-
X
Plan d'exécution
----------------------------------------------------------
Plan hash value: 272002086
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 2 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS FULL| DUAL | 1 | 2 | 2 (0)| 00:00:01 |
--------------------------------------------------------------------------
SQL> select /*+ PARALLEL(dual) */ * from dual;
D
-
X
Plan d'exécution
----------------------------------------------------------
Plan hash value: 1494853933
----------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | TQ |IN-OUT| PQ Distrib |
----------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 2 | 2 (0)| 00:00:01 | | | |
| 1 | PX COORDINATOR | | | | | | | | |
| 2 | PX SEND QC (RANDOM)| :TQ10000 | 1 | 2 | 2 (0)| 00:00:01 | Q1,00 | P->S | QC
| 3 | PX BLOCK ITERATOR | | 1 | 2 | 2 (0)| 00:00:01 | Q1,00 | PCWC | |
| 4 | TABLE ACCESS FULL| DUAL | 1 | 2 | 2 (0)| 00:00:01 | Q1,00 | PCWP | |
----------------------------------------------------------------------------------------------------
SQL> select /*+ PARALLEL(dual) */ * from dual d;
D
-
X
Plan d'exécution
----------------------------------------------------------
Plan hash value: 272002086
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 2 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS FULL| DUAL | 1 | 2 | 2 (0)| 00:00:01 |
--------------------------------------------------------------------------
SQL> select /*+ BIDON */ * from dual;
D
-
X
Plan d'exécution
----------------------------------------------------------
Plan hash value: 272002086
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 2 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS FULL| DUAL | 1 | 2 | 2 (0)| 00:00:01 |
--------------------------------------------------------------------------
Partager