"kukeltje" wrote : Can it be driver related as well? Or oracle version? Because as far as I know, Oracle is in the QA round. It doesn't have anything to do with oracle version or driver. As I already mentioned I'm almost sure that hibernate mappings for JBPM4_HIST_DETAIL table are not correct. Indexes are index="IDX_HDET_..." instead of "IDX_HDETAIL_..." (as they are defined for the other tables) and that causes hibernate to generate two indexex for the same column. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4248151#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...