Do you really expect to have more than 2^63 cases ever? Or why else would you not use 64 bit integers (long) for keys? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4107570#4107570 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4107570