PMON的一个关键功能就是在进程失败的时候清理死进程及其相关的资源。
我们来观看一下PMON清理死进程的过程，100246事件可以跟踪PMON的行为。
Event 10246 - Trace PMON Process
This event can be used to trace the actions of the PMON background process
This event can only be enabled in the init.ora file using
event = "10246 trace name context forever, level 1"
The ALTER SYSTEM command does not appear to work for this event
There only appears to be one level for this event (levels 5 and 10 appear to generate the same output as level 1)
SQL> show parameter event
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
event string 10246 trace name context forever,level 1
xml_db_events string enable
开启一个SESSION :
C:\Documents and Settings\htaix>sqlplus test/test@192.168.0.5/huateng
SQL*Plus: Release 10.2.0.1.0 - Production on 星期二 1月 29 11:14:31 2013
Copyright (c) 1982, 2005, Oracle. All rights reserved.
连接到:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> delete from x;
已删除12行。
SQL> select sid,serial#,paddr from v$session where sid=userenv('sid');
SID SERIAL# PADDR
---------- ---------- --------
39 10 2A83AC80
SQL> select spid from v$process where addr='2A83AC80';
SPID
------------------------
15428
然后在OS级别KILL掉相关的SERVER PROCESS:
SQL> !ps -ef | grep 15428
oracle 15428 1 0 01:03 ? 00:00:01 oraclehuateng (LOCAL=NO)
oracle 21234 13533 0 01:21 pts/0 00:00:00 /bin/bash -c ps -ef | grep 15428
oracle 21236 21234 0 01:21 pts/0 00:00:00 /bin/bash -c ps -ef | grep 15428
SQL> ! kill -9 15428
此时查询SESSION 会报ORA-03113错误：
SQL> select sid,serial#,paddr from v$session where sid=userenv('sid');
select sid,serial#,paddr from v$session where sid=userenv('sid')
*
第 1 行出现错误:
ORA-03113: 通信通道的文件结束
过一段时间后，将会在PMON TRACE文件中发现PMON清理死进程的过程：
*** 2013-01-25 01:22:21.372
marked process 0x2a83ac80 pid=31 serial=4 ospid = 15428 dead <-- OS PID =15428 标记为死进程
client details:
O/S info: user: htaix, term: HT002, ospid: 9532:3440
machine: WORKGROUP\HT002 program: sqlplus.exe
application name: SQL*Plus, hash value=3669949024
*** 2013-01-25 01:22:21.401
deleting process 0x2a83ac80 pid=31 serial=4 priority=0 <-- 开始清理死进程
deleting session 0x2aac6f9c sid=39 serial=10 <--清理 SESSION
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
ksuprog() called at ktur.c:3039
Audit postponed pending cleanup for session 0x2aac6f9c
deleting session 0x2aac6f9c sid=39 serial=11
Audit postponed pending cleanup for session 0x2aac6f9c
deletion of process 2a83ac80 pid=31 seq=4 prog=TRUE unsuccessful
*** 2013-01-25 01:22:21.447
found process 0x2a83ac80 pid=31 serial=4 ospid = 15428 dead
*** 2013-01-25 01:22:21.468
deleting process 0x2a83ac80 pid=31 serial=4 priority=0
deleting session 0x2aac6f9c sid=39 serial=12
deletion of process 2a83ac80 pid=31 seq=4 successful <--成功清理完毕死进程