[CentOS] Install Oracle XE

Unlike on Windows, installing Oracle XE on CentOS requires some more steps after the actual RPM installation.

After you download the zip file, extract it and install the RPM, browse to the Disk1 directory under the folder where you extracted everything into.

Now run as root

/etc/init.d/oracle-xe configure

to configure and start the database.

The installation process creates a /u01 folder, inside it, under app/oracle/product/VERSION_NUMBER/xe/bin you'll find the oracle_env.sh script which sets some environment variables used by Oracle for you.

To have it permanently set those variables for your user, add this line to your .bash_profile (found under your user home):

. /u01/app/oracle/product/VERSION_NUMBER/xe/bin/oracle_env.sh

After this, you should be able to run SQLPlus (you may have to log out and log in again or just open a new terminal window).