Oracle Hang Analysis
Author: rainnyzhong
Date:2010-1-15
1． 症状描述：
FALB12从EXCEL IMPORT DATA到DB，预计事务会运行1个多小时，在开始操作后40分钟左右，ORACLE挂死，任何用户都不可以再登陆了。
2． 分析
（1） 下面是挂死时OS的资源状况：
09:37:54 up 73 days, 23:31, 1 user, load average: 0.11, 0.24, 0.18
194 processes: 191 sleeping, 3 running, 0 zombie, 0 stopped
CPU states: cpu user nice system irq softirq iowait idle
total 6.7% 0.0% 0.3% 0.3% 0.0% 1.9% 90.4%
Mem: 2186616k av, 2168780k used, 17836k free, 0k shrd, 154716k buff
1633584k actv, 498176k in_d, 64108k in_c
Swap: 2040244k av, 18624k used, 2021620k free 2283068k cached
从top命令的输出中，我们可以看出，MEMORY使用几乎已经达到100%。
（2） 下面是ORACLE报警日志的内容：
Thu Jan 14 16:22:44 2010
Errors in file /opt/oracle9i/admin/ORA16G/udump/ora16g_ora_29758.trc:
ORA-00604: error occurred at recursive SQL level 4
ORA-04021: timeout occurred while waiting to lock object
ORA-00604: error occurred at recursive SQL level 4
ORA-04021: timeout occurred while waiting to lock object
ORA-00604: error occurred at recursive SQL level 3
ORA-04021: timeout occurred while waiting to lock object
Thu Jan 14 16:26:06 2010
可以看出，在解析递归SQL时出问题了，在等待某种锁时延时了。
（3） 下面是跟踪文件ora16g_ora_29758.trc的部分内容
*** 2010-01-14 16:22:44.412
================
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