Forum OpenACS Q&A: Re: Asian Characters and UTF-8 Encoding - Any experiences?

PS here's the Oracle note on how to convert your database character set:

http://metalink.oracle.com/metalink/plsql/ml2_documents.showDocument?p_id=66320.1&p_database_id=NOT

Quick summary: alter database character set UTF8;

Beware the dreaded ORA-12712: new character set must be a superset of old character set!

As I said your data is probably screwed, so there's no point running the conversion until you clean it up.