Database Patching
Database patching consists of either upgrades or interim fixes. Database upgrades are typically complex in nature and require installation of new software when upgrading from one point release to another. Obsolete and new initialization parameters must be reviewed when upgrading to a new release of the database.
Database upgrades can be accomplished manually or by using dbmig,the database migration utility. Since the method for upgrading the database is version and platform dependent, the associated readme file for the upgrade must be reviewed, and the steps required to perform the upgrade should be documented.
Interim patch fixes for the database are applied as the owner of the database install with the opatch utility or by running an operating system script. Details on how to apply database patches are outlined in the patch’s readme.Before upgrading or applying a patch to the database, the oraInst.loc file must point to the correct Oracle inventory location for the database ORACLE_HOME. It is also important to cleanly shut down the database before proceeding, and to perform a cold database backup.
The opatch utility is downloaded from MetaLink as patch number 2617419. The opatch utility requires Perl and JDK to function, and they must be installed and specified in the path and library environment variables. Once the opatch utility has been downloaded and unbundled, the Opatch directory of the opatch unbundled patch should be added to the PATH, as in the following example:
$export PATH=$PATH:/[path_of_2617419]/Opatch
The library path of Perl must also be specified with the following PERL5LIB environment variable, as in the following example:
$export PERL5LIB=[path_of_PERL]/lib
To validate that opatch is functioning properly, execute the following command with the lsinventory option:
$opatch lsinventory
Once opatch has been successfully set up, the database interim patch fix may be applied. To do this, first review the readme file for the patch. Make certain that all prerequisites have been met. Document any post-patching steps that are required. Download the patch and unbundle it. Change to the directory where the patch has been unbundled. Verify that the database has been shut down. Apply the patch by executing opatch as the database owner with the apply parameter, as in the following example:
$opatch apply
To verify that a patch has successfully been applied, the lsinventory option can again be executed. This will display all patches that have been applied to the database.
■Note If the opatch fails, there may be a patch_locked file located under the hidden directory $ORACLE_HOME/.patch_storage. The opatch utility may not be executed until the patch_locked file is removed.Labels: Database Patching |
