Oracle 每个季度都会发布最新的补丁。对于生产运维人员来说，定期升级系统、打补丁是日常工作中不可缺少的部分。
相对于过去的版本，Oracle打补丁的方式已经变得比较简单，处理PSU的方法也发生了一些变化。在11g中，对于一些小bug的修复，我们可以使用OPatch工具进行补丁修复。对于大的版本升级，Oracle的PSU实际上就是一系列全新的安装文件，从MOS上下载之后就可以直接进行安装。
1、关闭数据库
Oracle的PSU升级不更新数据字典，风险较小，但是还是需要停库进行升级操作。
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
停止监听服务。
[oracle@bntjftest 20299015]$ lsnrctl stop
检查服务进程
[oracle@bntjftest 20299015]$ ps aux | grep ora_
oracle 6922 0.0 0.0 5700 796 pts/3 S+ 17:48 0:00 grep ora_
[oracle@bntjftest 20299015]$ ps aux | grep tns
oracle 6924 0.0 0.0 5704 796 pts/3 S+ 17:48 0:00 grep tns
2、检查opatch版本信息，需要的话进行升级
[oracle@bntjftest OPatch]$ ./opatch version
OPatch Version: 11.2.0.1.7
OPatch succeeded.
检查发现opatch版本较低，为默认版本，所以需要升级opatch。升级方法很简单，直接mv掉原来的opatch目录，然后解压最新版本的opatch软件到ORACLE_HOME下面即可
[oracle@bntjftest OPatch]$ unzip p6880880_112000_Linux-x86-64-opatch .zip -d $ORACLE_HOME
再次检查版本，发现已经升级成功。
[oracle@bntjftest OPatch]$ ./opatch version
OPatch Version: 11.2.0.3.6
OPatch succeeded.
3、应用PSU补丁
1）插曲一、安装程序错误
[oracle@bntjftest OPatch]$ ./opatch apply ./20299015/
Oracle Interim Patch Installer version 11.2.0.3.6
Copyright (c) 2013, Oracle Corporation. All rights reserved.
Oracle Home : /app/oracle/product/11.2.0/dbhome_1
Central Inventory : /app/oraInventory
from : /app/oracle/product/11.2.0/dbhome_1/oraInst.loc
OPatch version : 11.2.0.3.6
OUI version : 11.2.0.4.0
Log file location : /app/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2015-05-14_10-45-03AM_1.log
Verifying environment and performing prerequisite checks...
Prerequisite check "CheckPatchApplicableOnCurrentPlatform" failed.
The details are:
Patch ( 20299015 ) is not applicable>UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed.
Log file location: /app/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2015-05-14_10-45-03AM_1.log
OPatch failed with error code 73
不使用自动模式，手工运行，一样报错：
[oracle@bntjftest 20299015]$ /app/oracle/product/11.2.0/dbhome_1/OPatch/opatch napply -skip_subset -skip_duplicate
Oracle Interim Patch Installer version 11.2.0.3.6
Copyright (c) 2013, Oracle Corporation. All rights reserved.
Oracle Home : /app/oracle/product/11.2.0/dbhome_1
Central Inventory : /app/oraInventory
from : /app/oracle/product/11.2.0/dbhome_1/oraInst.loc
OPatch version : 11.2.0.3.6
OUI version : 11.2.0.4.0
Log file location : /app/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2015-05-14_10-45-03AM_1.log
Verifying environment and performing prerequisite checks...
Prerequisite check "CheckPatchApplicableOnCurrentPlatform" failed.
The details are:
Patch ( 20299015 ) is not applicable>UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed.
Log file location: /app/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2015-05-14_10-45-03AM_1.log
OPatch failed with error code 73
上网baidu，“ UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed”， 很快就查到解决办法，明确了其实就是因为有用户进程占用了文件libclntsh.so.11
[oracle@bntjftest 20299015]$ /sbin/fuser /app/oracle/product/11.2.0/dbhome_1/lib/libclntsh.so.11 .1
/app/oracle/product/11.2.0/dbhome_1/lib/libclntsh.so.11.1: 16470m
[oracle@bntjftest 20299015]$ ps -ef | grep 16470
oracle 16470 5399 0 14:45 pts/2 00:00:00 sqlplus as sysdba
oracle 7780 6617 0 18:47 pts/3 00:00:00 grep 16470
[oracle@bntjftest 20299015]$ kill -9 16470
[oracle@bntjftest 20299015]$ /sbin/fuser /app/oracle/product/11.2.0/dbhome_1/lib/libclntsh.so.11.1
3）再次重新应用PSU补丁，成功