For Step #4 in Configuring an Oracle Datasource in Apache Tomcat, we've asked to define the Oracle hibernate dialect as "org.hibernate.dialect.OracleIntlDialect".

It's been reported that this no longer works and Confluence needs to use "net.sf.hibernate.dialect.OracleIntlDialect" as the dialect instead, as per the resolution outlined here: Confluence Upgrade Fails because Oracle could not Complete Schema Update.