在早期Oracle版本中，由于技术不成熟等原因，数据库锁定和僵死状态还是时有发生的。对待这些问题，老先生们的处理策略无外乎是“重启”和“考究”两种策略。所谓“重启”，通过强制的重启服务器或者数据库，将软硬件偶然出现的锁定僵死状态重置，是一种最简单的处理办法。但是，如果是应用程序层面潜在的缺陷、数据库的Bug或者诸如大规模事务回滚的情况，重启大法的作用是很有限的。况且，一些关键业务系统，重启数据库是需要很高级别的审批流程的。这个时候，就需要进行“考究”，仔细研究故障点进行精准分析。
“考究”的过程是非常复杂的。传统方法是将数据库内存状态全部dump到Trace文件中，从其中观察到各个进程之间复杂的交互关系，最后定位到数据库锁定的原因。
由于Oracle的负责性，Trace文本文件通常成千上万行，进行读取也是非常消耗精力的事情。数据库故障在任何企业都是大事故，每分每秒都意味着巨大的经济损失，早一分钟定位错误，解决问题，是有着重大意义的。
Linux体系对于正则表达式、文本处理是有很强的积淀的。AWK/SED命令就可以处理比较负责的文本分析问题。于是，行业中推出了结合awk命令使用的ass109.awk命令程序，实现快速的系统trace文件分析。
下面通过一个比较简单的会话间锁定测试，来演示awk命令处理思路。具体ass109.awk脚本在网络上下载比较方便，就不累列本文。
1、测试环境准备
实验环境选择Oracle 11gR2，版本为11.2.0.4。
SQL> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE 11.2.0.4.0 Production
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 – Production
实验场景找一个比较简单的就好，双Session共同更新相同记录，构成锁定状态。
--Session 1
SQL> create table t as select object_id from dba_objects;
Table created
SQL> select sid from v$mystat where rownum<2;
SID
----------
319
SQL> delete t where object_id=1000;
1 row deleted
--Session 2
SQL> select sid from v$mystat where rownum<2;
SID
----------
479
SQL> delete t where object_id=1000;
(Hang住)
319和479会话处在锁定等待状态。
2、数据库状态Trace
下面就需要将系统状态System State，笔者选择使用oradebug工具来进行处理。
[oracle@testlife trace]$ sqlplus /nolog
SQL*Plus: Release 11.2.0.4.0 Production on Fri Oct 14 20:01:13 2016
Copyright (c) 1982, 2013, Oracle. All rights reserved.
SQL> conn / as sysdba
Connected.
SQL> oradebug setmypid
Statement processed.
SQL> oradebug dump systemstate 10;
Statement processed.
SQL> oradebug tracefile_name;
/u01/app/oracle/diag/rdbms/testdb/testdb/trace/testdb_ora_8344.trc
定位到Trace File所在的目录，确认文件生成。同时，确定ass109处理文件也在该目录下。
[oracle@testlife trace]$ ls -l | grep testdb_ora_8344.trc
-rw-r----- 1 oracle oinstall 1021451 Oct 14 20:01 testdb_ora_8344.trc
[oracle@testlife trace]$ ls -l | grep ass109.awk
-rw-r--r-- 1 root root 34549 Oct 14 19:25 ass109.awk
3、分析处理
使用awk分析trace文件极其简单，分析结果直接就输出在屏幕中。
[oracle@testlife trace]$ awk -f ass109.awk testdb_ora_8344.trc
Starting Systemstate 1
............................
Ass.Awk Version 1.0.9 - Processing testdb_ora_8344.trc
System State 1
~~~~~~~~~~~~~~~~
1:
2: 0: waiting for 'pmon timer'
3: 0: waiting for 'rdbms ipc message'
4: 0: waiting for 'VKTM Logical Idle Wait'
5: 0: waiting for 'rdbms ipc message'
6: 0: waiting for 'DIAG idle wait'
7: 0: waiting for 'rdbms ipc message'
8: 0: waiting for 'DIAG idle wait'
9: 0: waiting for 'rdbms ipc message'
10: 0: waiting for 'rdbms ipc message'
11: 0: waiting for 'rdbms ipc message'
12: 0: waiting for 'rdbms ipc message'
13: 0: waiting for 'smon timer'
14: 0: waiting for 'rdbms ipc message'
15: 0: waiting for 'rdbms ipc message'
16: 0: waiting for 'rdbms ipc message'
17:
18:
19: 0: waiting for 'rdbms ipc message'
20: 0: waiting for 'Streams AQ: qmn coordinator idle wait'
21: 0: waiting for 'rdbms ipc message'
22: 0: waiting for 'Streams AQ: qmn slave idle wait'
23: 0: waiting for 'Streams AQ: waiting for time management or cleanup tasks'
24: 0: waiting for 'Space Manager: slave idle wait'
25: 0: waiting for 'SQL*Net message from client'
26: 0: waiting for 'SQL*Net message from client'
27: 0: waiting for 'enq: TX - row lock contention'[Enqueue TX-00060002-00000611]
28:
Blockers
~~~~~~~~
Above is a list of all the processes. If they are waiting for a resource
then it will be given in square brackets. Below is a summary of the
waited upon resources, together with the holder of that resource.
Notes:
~~~~~
o A process id of '???' implies that the holder was not found in the
systemstate.
Resource Holder State
Enqueue TX-00060002-00000611 26: 0: waiting for 'SQL*Net message from client'
Object Names
~~~~~~~~~~~~
Enqueue TX-00060002-00000611
18642 Lines Processed.