/*+append*/ nologging 2000W的数据 用时是原来的1/3

实践了下 /*+append*/ nologging
2000W的数据 用时是原来的1/3

SQL> set autotrace traceonly
SQL> insert into awen.ob_bak2 select * from awen.ob_com;

已创建19364384行。


执行计划
----------------------------------------------------------
Plan hash value: 521658461

----------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------
| 0 | INSERT STATEMENT | | 19M| 3323M| 283K (2)| 00:05:44 |
| 1 | TABLE ACCESS FULL| OB_COM | 19M| 3323M| 283K (2)| 00:05:44 |
----------------------------------------------------------------------------

Note
-----
- dynamic sampling used for this statement


统计信息
----------------------------------------------------------
0 recursive calls
0 db block gets
0 consistent gets
0 physical reads
0 redo size
0 bytes sent via SQL*Net to client
0 bytes received via SQL*Net from client
0 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
19364384 rows processed

SQL> select sysdate from dual;

SYSDATE
-------------------
2012-04-12 13:49:52

SQL> insert /*+append*/ into awen.ob_bak2 select * from awen.ob_com nologging;

已创建19364384行。


执行计划
----------------------------------------------------------
ERROR:
ORA-12838: 无法在并行模式下修改之后读/修改对象


SP2-0612: 生成 AUTOTRACE EXPLAIN 报告时出错

统计信息
----------------------------------------------------------
0 recursive calls
0 db block gets
0 consistent gets
0 physical reads
0 redo size
0 bytes sent via SQL*Net to client
0 bytes received via SQL*Net from client
0 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
19364384 rows processed

SQL> select sysdate from dual;

SYSDATE
-------------------
2012-04-12 13:51:45