10500事件跟踪SMON进程
SMON进程是ORACLE的一个关键进程，负责INSTANCE RECOVERY，清理临
时段，合并空闲空间，收缩回滚段，维护SMON_SCN_TIME表等。
我们可以通过10500事件来跟踪上述行为：
www.2cto.com
Level: <=5 trace instance recovery
> 5 trace posting of SMON
首先开启一个SESSION 删掉一些数据
SQL> delete test;
已删除48875行。 www.2cto.com
SQL>
C:>sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on 星期一 1月 21 18:00:40 2013
Copyright (c) 1982, 2005, Oracle. All rights reserved.
连接到:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> alter system set event='10500 trace name context forever,level 10' scope=spfile;
系统已更改。 www.2cto.com
ORACLE 例程已经启动。
Total System Global Area 176160768 bytes
Fixed Size 1247900 bytes
Variable Size 104858980 bytes
Database Buffers 58720256 bytes
Redo Buffers 11333632 bytes
数据库装载完毕。
数据库已经打开。
www.2cto.com
从SMON的TRACE文件可以看到SMON的行为：
Dump file c:oracleproduct10.2.0adminplsqldbbdumpplsqldb_smon_5604.trc
Mon Jan 21 19:25:36 2013
ORACLE V10.2.0.1.0 - Production vsnsta=0
vsnsql=14 vsnxtr=3
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Windows XP Version V5.1 Service Pack 3
CPU : 4 - type 586, 2 Physical Cores
Process Affinity : 0x00000000
Memory (Avail/Total): Ph:1777M/3240M, Ph+PgF:3242M/5125M, VA:1729M/2047M
Instance name: plsqldb
Redo thread mounted by this instance: 0
Oracle process number: 8
Windows thread id: 5604, image: ORACLE.EXE (SMON)
*** SERVICE NAME:() 2013-01-21 19:25:36.437
*** SESSION ID:(120.1) 2013-01-21 19:25:36.437
*** 2013-01-21 19:25:36.437
SMON: system monitor started
*** 2013-01-21 19:25:36.718
SMON: system monitor process posted
*** 2013-01-21 19:25:54.593
SMON: system monitor process posted
*** 2013-01-21 19:25:54.812
SMON: system monitor process posted
*** 2013-01-21 19:25:57.765
SMON: system monitor process posted
Dead transaction 0x0009.01f.000002e5 recovered by 8 server(s) <----SMON开启了8个PROCESS进行事务的恢复。
*** 2013-01-21 19:26:06.078
SMON: Parallel transaction recovery tried
*** 2013-01-21 19:26:12.546
Shrinking rbseg #0 <--收缩临时段 www.2cto.com
*** 2013-01-21 19:26:12.546
Shrinking rbseg #1
*** 2013-01-21 19:26:12.562
Shrinking rbseg #2
*** 2013-01-21 19:26:12.562
Shrinking rbseg #3
*** 2013-01-21 19:26:12.578
Shrinking rbseg #4
*** 2013-01-21 19:26:12.578
Shrinking rbseg #5
*** 2013-01-21 19:26:12.593
Shrinking rbseg #6
*** 2013-01-21 19:26:12.609
Shrinking rbseg #7
*** 2013-01-21 19:26:12.625
Shrinking rbseg #8
*** 2013-01-21 19:26:12.625
Shrinking rbseg #9
*** 2013-01-21 19:26:12.625
Shrinking rbseg #10
*** 2013-01-21 19:26:12.640
SMON: system monitor process posted
*** 2013-01-21 19:26:12.640
SMON: Posted too frequently, trans recovery disabled.