Steps:-
Follow the below steps to install the 11g database(latest when this post was written)
Download the latest oracle version for ubuntu

1. Unzip using the command:

   unzip oracle-xe-11.2.0-1.0.x86_64.rpm.zip 

2. Install required packages using the command:

   sudo apt-get install alien libaio1 unixodbc

3. Convert RPM package format to DEB package format (that is used by Ubuntu) using the command:

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

4. Create the required chkconfig script using the command::

   sudo pico /sbin/chkconfig

   The pico text editor is started and the commands are shown at the bottom of the screen. Now copy and paste the following into the file and save:

   
   #!/bin/bash
   # Oracle 11gR2 XE installer chkconfig hack for Ubuntu
   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
   

5. Change the permission of the chkconfig file using the command:

   sudo chmod 755 /sbin/chkconfig  

6. Set kernel parameters. Oracle 11gR2 XE requires additional kernel parameters which you need to set using the command:

   sudo pico /etc/sysctl.d/60-oracle.conf

   Copy the following into the file and save:

   # Oracle 11g XE kernel parameters  
   fs.file-max=6815744  
   net.ipv4.ip_local_port_range=9000 65000  
   kernel.sem=250 32000 100 128 
   kernel.shmmax=536870912 
   

   Verify the change using the command:

   sudo cat /etc/sysctl.d/60-oracle.conf 
   

   You should see what you entered earlier. Now load the kernel parameters:

   sudo service procps start
   

   Verify the new parameters are loaded using:

   sudo sysctl -q fs.file-max
   

   You should see the file-max value that you entered earlier.

7. Set up /dev/shm mount point for Oracle. Create the following file using the command:

   sudo pico /etc/rc2.d/S01shm_load
   

   Copy the following into the file and save.

   #!/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 
   

   Change the permissions of the file using the command:

   sudo chmod 755 /etc/rc2.d/S01shm_load
   

8. [This step was not included in the screencast, but you should do it.] Execute the following commands:

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

9. REBOOT your Ubuntu VM.
10. Install the oracle DBMS using the command:

    sudo dpkg --install oracle-xe_11.2.0-2_amd64.deb
    

11. Configure Oracle using the command:

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

    Enter the following information:

    • A valid HTTP port for the Oracle Application Express (the default is 8080)
    • A valid port for the Oracle database listener (the default is 1521)
    • A 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 (next reboot).
12. Setup environment variables by editting your .bashrc file:

    pico ~/.bashrc
    

    Add the following lines to the end of the file:

    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
    

    Load the changes by executing your profile:

    . ~/.profile
    

13. Start the Oracle 11gR2 XE:

    sudo service oracle-xe start
    

14. Add user YOURUSERNAME to group dba using the command

    sudo usermod -a -G dba YOURUSERNAME

15. Start the Oracle XE 11gR2 server using the command:

    sudo service oracle-xe start
    

    This step is most likely not necessary, but I am documenting the command here anyway.

16. Start command line shell as the system admin using the command:

    sqlplus sys as sysdba
    

    Enter the password that you gave while configuring Oracle earlier. You will now be placed in a SQL environment that only understands SQL commands.

17. Create a regular user account in Oracle using the SQL command:

    create user USERNAME identified by PASSWORD;
    

    Replace USERNAME and PASSWORD with the username and password of your choice. Please remember this username and password.

18. Grant privileges to the user account using the SQL command:

    grant connect, resource to USERNAME;
    

    Replace USERNAME and PASSWORD with the username and password of your choice. Please remember this username and password.

19. Exit the sys admin shell using the SQL command:

    exit;
    

20. Start the commandline shell as a regular user using the command:

    sqlplus
    

    You will be prompted for a username and password. Once authenticated, you will be able to type in the standard SQL commands learned in class.

B) After our successfull installation of oracle, we are going to configure sql developer IDE.

Download the latest sql developer edition
1.sudo alien –scripts -d sqldeveloper-version.noarch.rpm
A file named sqldeveloper_version_all.deb will be generated. To run this file, execute the following statement:

2.sudo dpkg –install sqldeveloper_version_all.deb
Create a .sqldeveloper directory in your home folder:

3.sudo mkdir /home/.sqldeveloper/
Run SQL Developer from the terminal.

4.sudo /opt/sqldeveloper/sqldeveloper.sh
5.Enter the path for java installed on your system
How to find path by using the command whereis jvm
generally its installed inside /usr/lib/jvm/java-version

$ sudo alien --scripts -d sqldeveloper-4.2.0.17.089.1709-1.noarch.rpm
[sudo] password for user: 
sqldeveloper_4.2.0.17.089.1709-2_all.deb generated
user@test:~/Documents/Northstar/oracle$ sudo dpkg --install sqldeveloper_4.2.0.17.089.1709-2_all.deb 
Selecting previously unselected package sqldeveloper.
(Reading database ... 277479 files and directories currently installed.)
Preparing to unpack sqldeveloper_4.2.0.17.089.1709-2_all.deb ...
Unpacking sqldeveloper (4.2.0.17.089.1709-2) ...
Setting up sqldeveloper (4.2.0.17.089.1709-2) ...
Processing triggers for libc-bin (2.23-0ubuntu7) ...
user@test:~/Documents/test/oracle$ sudo mkdir /home/.sqldeveloper/ms@test:~/Documents/test/oracle$ sudo /opt/sqldeveloper/sqldeveloper.sh

 Oracle SQL Developer
 Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.

Type the full pathname of a JDK installation (or Ctrl-C to quit), the path will be stored in /home/mandeep/.sqldeveloper/4.2.0/product.conf
/usr/lib/jvm/java-1.8.0-openjdk-amd64

6.Accept the default settings for any window pop ups

7. All done, check the first look of SQL developer to work with oracle.

Note:-
Login as sys user using terminal:-
 sqlplus / as sysdba , enter username and password > execute the queries

Reference documents:-
http://www2.hawaii.edu/~lipyeow/ics321/2014fall/installoracle11g.html