I recently installed Oracle XE on my laptop and tried to run our project which normally uses Oracle 10g in our company. After creating a db user and enabling it, I created tables, sequences, triggers and stored procedures etc by running db init scripts through ant without any problem. When it came to starting application in application server, I got “ORA-12519, TNS:no appropriate service handler found” messages. Thanks to this and this blog entries to reach at a quick solution. The problem was a bug in how Oracle XE handles monitoring processes, and you need to execute “ALTER SYSTEM SET PROCESSES=150 SCOPE=SPFILE;” statement and then restart your database to get rid of it.
After overcoming this problem, I came up with a Turkish character encoding problem within my Hibernate generated sql statements but I am not hundred percent sure if I installed Oracle XE to deal with non latin characters appropriately. Anyway, it is easy to get rid of such encoding problems by setting user.language and user.country system properties to en and US consecutively.