I recently pushed 'database_initializer.rb' to github @http://github.com/NiranjanSarade/oracle_xe_database_initializer. Please check its README for more information.
This can be used to set up your schema and other database objects in your local Oracle XE database. The script assumes that you have following set up on your machine :-
1. Oracle client
2. activerecord-oracle_enhanced-adapter gem
3. Oracle XE (http://www.oracle.com/technetwork/database/express-edition/downloads/index.html)