Hi Mircea, Thanks for the hints, I looked at the debug log, the sql statement being logged right before the exception is not a "INSERT INTO, but a select": | | DEBUG JDBCCacheLoader - executing sql: select fqn from Cached_Events where parent=? (/) | | I tries to execute the statement: select fqn from Cached_Events where parent='/', it finds something in the table. The 1st insert into statement is logged far after the exception is logged. This is the log msg for it, and it is surprisingly involving the automatically created table 'cached_events_d': | DEBUG JDBCCacheLoader - executing sql: INSERT INTO Cached_Events (fqn, node, parent) SELECT ?, ?, ? FROM Cached_Events_D WHERE NOT EXISTS (SELECT fqn FROM Cached_Events WHERE fqn = ?) (/RTDE/time-distance-analysis-gps/0) | I don't know how to execute this in the console (Oracle SQL Developer) Any idea? Xuetao View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4241194#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...