Oracle Enterprise Linux 4, Update 6 or Newer
# cd /etc/yum.repos.d
# mv Oracle-Base.repo Oracle-Base.repo.disabled
# wget http://public-yum.oracle.com/public-yum-el4.repo
Oracle Enterprise Linux 5
# cd /etc/yum.repos.d
# wget http://public-yum.oracle.com/public-yum-el5.repo
Oracle Enterprise Linux 6
# cd /etc/yum.repos.d
# wget http://public-yum.oracle.com/public-yum-ol6.repo
Oracle VM 2
# cd /etc/yum.repos.d
# wget http://public-yum.oracle.com/public-yum-ovm2.repo
Enable the appropriate repository by editing the yum configuration file
* Open the yum configuration file in a text editor
* Locate the section in the file for the repository you plan to update from, e.g. [el4_u6_base]
* Change enabled=0 to enabled=1
Test with
yum list