Instalación del servidor oracle xe (express edition) 11g en ubuntu
Sacado de https://www.programmersought.com/article/404491792/, con alguna adaptación


1. execute the following command, install alien, used to convert rpm to deb
[En vez de vim, que es lo que aparece en la página, he utilizado nano, que es un editor más sencillo]

sudo apt-get install alien libaio1 unixodbc nano

2. Download Oracle 11g express edition installation file from Oracle official website
http://www.oracle.com/technetwork/database/database-technologies/express-edition/downloads/index.html
[Conectarse a la web de oracle, buscar la versión xe 11g, descargarlo y descomprimirlo. Para versiones posteriores no sé si funcionará.]

3. convert the rpm installation file to a deb file
[este es el nombre que debería tener el fichero descargado en su versión xe 11g. Lo convertimos a un fichero deb usando alien]

sudo alien --scripts -d oracle-xe-11.2.0-1.0.x86_64.rpm

4. preparation work
4.1. Create a chkconfig script file

sudo nano /sbin/chkconfig

[Editamos el fichero con nano y pegamos al final el siguiente código. Salir con control-x]

#!/bin/bash
file=/etc/init.d/oracle-xe
if [[ ! `tail -n1 $file | grep INIT` ]]; then
echo >> $file
echo '### BEGIN INIT INFO' >> $file
echo '# Provides: OracleXE' >> $file
echo '# Required-Start: $remote_fs $syslog' >> $file
echo '# Required-Stop: $remote_fs $syslog' >> $file
echo '# Default-Start: 2 3 4 5' >> $file
echo '# Default-Stop: 0 1 6' >> $file
echo '# Short-Description: Oracle 11g Express Edition' >> $file
echo '### END INIT INFO' >> $file
fi
update-rc.d oracle-xe defaults 80 01


4.2. Save the above file and modify the permissions

sudo chmod 755 /sbin/chkconfig


4.3. Execute the following commands

free -m
sudo ln -s /usr/bin/awk /bin/awk
mkdir /var/lock/subsys
touch /var/lock/subsys/listener


5. Execute the following command to prevent an error during Oracle installation.
(Ignore the error during execution)

sudo -s
umount /dev/shm
sudo rm -rf /dev/shm
sudo mkdir /dev/shm
mount --move /run/shm /dev/shm
sudo mount -t tmpfs shmfs -o size=2048m /dev/shm


5.1 Create the following file

sudo nano /etc/rc2.d/S01shm_load

5.2 Copy the following to the new file above
[Igual que antes, editamos el fichero y copiamos esto al final, salir con control x]

#!/bin/sh
case "$1" in
start) mkdir /var/lock/subsys 2>/dev/null
touch /var/lock/subsys/listener
rm /dev/shm 2>/dev/null
mkdir /dev/shm 2>/dev/null
mount -t tmpfs shmfs -o size=2048m /dev/shm ;;
*) echo error
exit 1 ;;
esac


5.3 Execute the following command

sudo chmod 755 /etc/rc2.d/S01shm_load


6. restart the computer

7. install Oracle 11gR2 XE
7.1 Enter the directory where the Oracle 11gR2 XE installation file is located.

7.2 Run the installation package
[puede que el fichero no se llame así, comprobar el nombre]

sudo dpkg --install oracle-xe-11.2.0-1.0.x86_64.deb

7.3 Running the configuration program

sudo /etc/init.d/oracle-xe configure


Enter the following configuration information:

- Valid HTTP port for the Oracle Application Express (the default is 8080, use 7070)
- Valid port for the Oracle database listener (the default is 1521)
- Password for the SYS and SYSTEM administrative user accounts
- Confirm password for SYS and SYSTEM administrative user accounts
- Whether you want the database to start automatically when the computer starts, Y

[ahora tardará un ratito continuando con la instalación]

8. Oracle 11gR2 XE necessary configuration before use
Environment variable configuration

8.1 Enter user directory

cd ~

8.2 Edit bashrc file

nano .bashrc

8.3 Add the following to the end of the .bashrc file
[igual que antes]

export ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe
export ORACLE_SID=XE
export NLS_LANG=`$ORACLE_HOME/bin/nls_lang.sh`
export ORACLE_BASE=/u01/app/oracle
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH
export PATH=$ORACLE_HOME/bin:$PATH

8.4 Execute the following command, the current bash environment variable takes effect.
[a mí no me ha funcionado]

./.profile

[he hecho esto]:

. ~/.profile

8.5 Edit the configuration file under the root user to copy the same content to the end of the file.

sudo nano /root/.bashrc

[de nuevo copiamos el trozo de código anterior, esta vez en el el fichero de root]

export ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe
export ORACLE_SID=XE
export NLS_LANG=`$ORACLE_HOME/bin/nls_lang.sh`
export ORACLE_BASE=/u01/app/oracle
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH
export PATH=$ORACLE_HOME/bin:$PATH


9. restart the computer, Oracle should run normally

10. Run the following command to enter the SQL prompt window.
[la contraseña es la que hemos puesto en la instalación]

sqlplus sys as sysdba