Oracle升级到11.2.0.3后，会存在一系列的Performance or Wrong Results，根据metalink文档ID 1392633.1说明，修复情况如下：
Scope
This note concerns itself with highly desirable patches in 11.2.0.3 that are not included in PSU updates,either because they contain optimizer layer fixes or because the PSU that will contain them has not yet been released.
Things to Consider Before Upgrading to 11.2.0.3 to Avoid Poor Performance or Wrong Results
While we try and include important fixes in the PSUs that are released on a quarterly basis, there are restrictions as to what can go into a PSU. One of the restrictions is fixes that may change execution plans, i.e. optimizer layer fixes. The reason for this is that it reduces the amount of testing required to go from one PSU to another. Other fixes may not yet have been released in a PSU.
Please consider applying the following patches, in addition to the latest PSU, to avoid certain performance, ORA-600/ORA-7445, and wrong results issues.
Patches relevant for all platforms
Patch:13656236Merge patch fixing the following two bugs:
Document:13004894.8Wrong results with SQL_TRACE / 10046
Document:13370330.8Bug 13370330 - ORA-600 [qkeIsExprReferenced1] From Query With Virtual Column
Patch:13831007MERGE REQUEST ON TOP OF 11.2.0.3.0 FOR BUGS 12797420 13588248
This merge includes 3 fixes in the area of Mutex Contention plus addresses a regression created by one of them. This merge can be used on either 11.2.0.3.0 or 11.2.0.3.1. We are hoping to have them included in the 11.2.0.3.2 PSU.
在linux上安装上述补丁，没什么问题；不过在AIX上安装下面的patch就出现了一些异常。
Patches specific to IBM AIX
Patch:12412983AIX: "asynch descriptor resize" wait not necessary on AIX
Patch:12596494GENERALLY HIGHER CPU USAGE IN 11.2.0.2 THAN 10.2.0.4
Patch:13443029MEMORY LEAK FIX FOR ONLINE PATCHING / HOT PATCHING
This reduces memory usage associated with the online patching feature.
AIX 6.1 TL7 or above (such as AIX 7.1) must be installed before either installing the patch or relinking the Oracle binary for it to be effective. If you are on an earlier version of AIX, then you may wish to consider installingPatch:10190759instead, but keep in mind that doing so will disable online patching.
在测试环境aix6106中，安装Patch:10190759后，数据库启动会产生ORA-07445: exception encountered: core dump [PC:0x0] [SIGILL] [ADDR:0x0] [PC:0x0] [Illegal opcode] []，后来安装Patch:13443029就没问题了，可能与我的系统环境有关吧......
Please seethis notefrom IBM for more information.
13343438这个补丁：如果在安装PSU到11.2.0.3.1时，会和PSU冲突，如果升级到11.2.0.3.0后需安装PSU，建议先不要安装这个patch。
如下所示：
[oracle@p520 p13348650]$ /oracle/app/oracle/product/11.2.0.3/OPatch/opatch prereq CheckConflictAgainstOHWithDetail -phBaseDir ./13348650/custom/server/13348650 -oh /oracle/app/oracle/product/11.2.0.3
Oracle Interim Patch Installer version 11.2.0.3.0
Copyright (c) 2012, Oracle Corporation. All rights reserved.
PREREQ session
Oracle Home : /oracle/app/oracle/product/11.2.0.3
Central Inventory : /oracle/app/oraInventory
from : /oracle/app/oracle/product/11.2.0.3/oraInst.loc
OPatch version : 11.2.0.3.0
OUI version : 11.2.0.3.0
Log file location : /oracle/app/oracle/product/11.2.0.3/cfgtoollogs/opatch/opatch2012-04-01_14-50-11PM_1.log
Invoking prereq "checkconflictagainstohwithdetail"
ZOP-40: The patch(es) has conflicts with other patches installed in the Oracle Home (or) among themselves.
Prereq "checkConflictAgainstOHWithDetail" failed.
Summary of Conflict Analysis:
There are no patches that can be applied now.
Following patches have conflicts. Please contact Oracle Support and get the merged patch of the patches :
12412983, 13343438
Following patches will be rolled back from Oracle Home on application of the patches in the given list :
12412983
Conflicts/Supersets for each patch are:
Patch : 13343438
Conflict with 12412983
Conflict details:
/oracle/app/oracle/product/11.2.0.3/lib/libserver11.a:/ksfd.o
OPatch succeeded.
如果已安装了原补丁，建议回滚冲突的补丁，再继续安装PSU
/oracle/app/oracle/product/11.2.0.3/OPatch/opatch rollback -local -oh /oracle/app/oracle/product/11.2.0.3 -id 12412983
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