I'm actually working on a application using OCI on an Oracle 11gr2. The Oracle client as the 11.2.0 version, was fully(admin) installed and configured with the same NLS_LANG variable as the DB.
In the Database, we are using CLOB to store long text files. The setup our application was writing the initial CLOB correctly, but we cant read it, we just a part of the text.
I checked it in SQLPlus and SQLDeveloper :
select sourcecode from script where name like 'callback';