the bmp choice is "select mysequence.next from dual;" for oracle and in the case of cmp the entitypersistancemanager will compute the pk.
but have a look at: GUIDs without Singletons and Databases http://www.theserverside.com/patterns/thread.jsp?thread_id=4976 and CMP Primary Key Sequence Generated By Bean Self Cache http://www.theserverside.com/patterns/thread.jsp?thread_id=5285 beware of using instance specific uid generation in a clustered environment !!!! you will definetly running into inconsistence if the cluster instances are connected into the cluster via a 'clustering backbone network' which is out of order and they have a living database connection via the 'database backbone network' and are still up and running. so every instance will work on its own and generate probably the same primary keys, because they do not know about each other. the safe way is the database roundtrip via sequence or trigger. there are serveral strategies to reserve a bulk of pk's in one transaction and use them subsequently - the highbyte-lowbyte pk approach to prevent database roundtrips. hth bax ----- Original Message ----- From: "Anthony Geoghegan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, August 12, 2002 3:26 PM Subject: [JBoss-user] Oracle sequence with CMP > Is there anyway of using an Oracle sequence with CMP in JBOSS 3.0.1? > Any indication I have is that you must use BMP > Best Regards, > Anthony Geoghegan. > J2EE Developer > CPS Ireland Ltd. > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > JBoss-user mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/jboss-user ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ JBoss-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-user
