怎样使用"10203"事件跟踪Oracle块清除

来源：赛迪网    作者：10933

我们知道，Oracle中的10203事件可以用来跟踪数据库的块清除（cleanout）操作,我们从事件列表中，可以知道该时间的含义为："block cleanout"。

10203事件需要在系统级设置，重启后即可生效：

SQL> alter system set event="10203 trace name context forever" scope=spfile;

System altered.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area  126948772 bytes
Fixed Size                   452004 bytes
Variable Size              92274688 bytes
Database Buffers           33554432 bytes
Redo Buffers                 667648 bytes
Database mounted.
Database opened.

SQL> show parameter event

NAME                      TYPE        VALUE
----------------------------------------------------------
event                     string      10203 trace name context forever

注释：在跟踪文件中，你现在即可以发现以下的block cleanout 信息：

Begin cleaning out block ...
Found all committed transactions
Block cleanout record, scn:  0xffff.ffffffff ver: 0x01 opt: 0x02, entries follow...
  itli: 1  flg: 2  scn: 0x0819.0045cd54
Block cleanout under the cache...
Block cleanout record, scn:  0x0819.0045cea1 ver: 0x01 opt: 0x02, entries follow...
  itli: 1  flg: 2  scn: 0x0819.0045cd54
... clean out dump complete.