>At the risk of giving you the podium, I would like to here more about >"second generation entity architecture" which IYHO mitigates the concern of >fine grained entities being too heavy weight. > >Regards, > >-Chris. It is well known that CORBA-based or Jdk1.1-based EJB implementations don't have adequate support for releasing entity objects (i.e. the remote interface implementation and *not* the bean instance). Some vendors (see the list archives) have implemented smart mechanisms to retire entity objects after a certain timeout (in a quasi-session object fashion). I call such mechanisms 1st generation entity architectures. Java 2-based EJB servers, however, have platform support to release only the entity objects that are not referenced anymore by either local or remote "clients". An entity architecture that takes advantage of the DGC facilities of the platform would fall into the 2nd generation category. Why is this important at all? To minimize the number of ejbLoads the server needs to perform on behalf of your client. For example, let's assume that you have a trading, bidding or auctioning application. In general, an application where a large number of quasi-temporary data is processed and filtered and a more-or-less constant number of instances are kept around. And, of course, let's also assume that you decided to model trades, bids etc. as entity beans since they need to be shared (i.e. referenced later, reported on, processed at the end of the month for statistics etc.). With a 1st generation architecture, the incoming trades, bids will very quickly fill up the available system tables and the server will start retiring the older entity objects regardless of whether they are still referenced or not. A 2nd generation system will be able to release entity objects more selectively keeping the referenced once alive and most probably even active. When your users start to ask for reports, in the second case, the entity objects (with the highest trade, bid etc) will be around and ejbLoad will not be mandatory. There is a lot more detail, however, I think the above pretty much describes what I have in mind when I refer to 2nd generation entity architectures. Imre Kifor Valto Systems =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
