This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I think it would be far better to do a manual setup of the DB instead of using the ubuntu software management. Download the rpm package for the XE from the oracle website here and follow the instructions on how to set it up.
Muhammad Saif Asif Mirza
OCJA(5/6) OCJP(6) OCJWCD(6)