How to apply Database Patches

Hi,
Database patches are of various kinds like,But in broad there are II types:
I)Patchset: To upgrade to higher version we use Database patchset.i.e For Upgrading from 10.2.0.1.0 to 10.2.0.4.0 we have to use
Patchset.

II)Patchset Updates:
Patchset Updates are mainly divided into two types:

1)CPU(Critical Patch Update):
Critical Patch Update, quarterly delivered by Oracle to fix security issues.

2)PSU(Patch Set Update):
PatchSet Update, also quarterly delivered by Oracle,it includes CPU and a bunch of other one-off patches.

PSUs have been introduced for the first time on Oct-2009,We can use them, and stop to apply CPUs. PSUs, as CPUs, are cumulatives, no need to apply all of them, just apply the last one should be enough. One-off patch is single fix, to fix a particular issue.

We need to have metalink(My Oracle Support)Account to download this patch and applying instructions will be there in readme file of Patch.

1)How to apply Patchsets:
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Patchsets are applied via OUI(Oracle Universal Installer).Patchsets are usually applied to upgrade oracle version
Eg: When we want to upgrade from Base release 10.2.0.1.0 to 10.2.0.4.0 for more useful feature and to avoid bugs,We have to use Patchset 10.2.0.4.0.So Patchsets change the version number.
Details of this process is there in the below mentioned link:

http://rafioracledba.blogspot.com/search/label/Database%20Upgrade
i.e Database Upgrade Label

2)How to apply Patch set updates or Critical Patch Updates:
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PSUs(PatchSet Updates) or CPUs(Critical Patch Updates)are applied via opatch utility.
opatch is an interim utility for applying Database interim patches which will fix the bug in the release. For making use of the opatch utility you have to download the opatch recent version and apply as follow:


Downloading and installing the latesh Opatch version:
------------------------------------------------------
Below are the steps for downloading and installing the latest opatch version.opatch is very much useful for applying the database patches to fix various bugs and it is very much important to have the latest version.

1) Please download the latest OPatch version from My Oracle Support (MOS)

a) Click on the "Patches & Updates" tab

b) In the "Patch Name or Number" field type 6880880

c) In the "Platform" field select the relevant platform

d) Click the Search button.

e) Select the patch that corresponds to the Oracle release installed:

6880880 Universal Installer: Patch OPatch 11.2

f) Click the Download button
Once the above task is done copy the patch to $ORACLE_HOME directory and move the previous OPatch directory to separate directory in OS.We can use winscp or ftp for copying this patch from MOS to windows and
than windows to linux Box.

Now,unzip this patch zip file.The files will be extracting as shown below:

Eg:
-----
$ cd $ORACLE_HOME
(If an OPatch directory already exist then move it)
$ mv Opatch /TEST/OPatch_100057
$cd $ORACLE_HOME
$ unzip p6880880_101000_LINUX64.zip
Archive: p6880880_101000_LINUX64.zip
creating: OPatch/
creating: OPatch/docs/
inflating: OPatch/docs/FAQ
inflating: OPatch/docs/README.txt
inflating: OPatch/docs/Users_Guide.txt
inflating: OPatch/docs/bt1.txt
inflating: OPatch/docs/bt2.txt
inflating: OPatch/docs/tmp
inflating: OPatch/emdpatch.pl
creating: OPatch/jlib/
inflating: OPatch/jlib/opatch.jar
inflating: OPatch/opatch
inflating: OPatch/opatch.bat
inflating: OPatch/opatch.pl

[oracle@kor300949lx1 OPatch]$ opatch version
Invoking OPatch 11.2.0.1.5

OPatch Version: 11.2.0.1.5

OPatch succeeded.

[oracle@kor300949lx1 OPatch]$ opatch apply /u01/app/8264365
Invoking OPatch 11.2.0.1.5

Oracle Interim Patch Installer version 11.2.0.1.5
Copyright (c) 2010, Oracle Corporation. All rights reserved.


Oracle Home : /u01/app/oracle/product/11.1.0/db_1
Central Inventory : /u01/app/oraInventory
from : /etc/oraInst.loc
OPatch version : 11.2.0.1.5
OUI version : 11.2.0.1.0
OUI location : /u01/app/oracle/product/11.1.0/db_1/oui
Log file location : /u01/app/oracle/product/11.1.0/db_1/cfgtoollogs/opatch/opatch2011-05-16_17-18-01PM.log

Patch history file: /u01/app/oracle/product/11.1.0/db_1/cfgtoollogs/opatch/opatch_history.txt

Here is your opatch latest version ready,Let us what all it consists of:

Go to the below mentioned path for all opatch commands description.

$ cd $ORACLE_HOME/OPatch/docs/
$ vi Users_Guide.txt

In general for applying any patch,We have to use the below command:
$cd $ORACLE_HOME/OPatch
$opatch apply /u01/Patch_dir/

Where :/u01/Patch_dir: The path where you have kept your Patch in the OS.

Hope the above post helps in understanding Database patches completely.

Best regards,

Rafi.