Hi again, -So the performance hit you're trying to overcome is that of having a db r/w for each field? -And use a transaction for the setData/getData method so that all fields are read/written in one shot? If that's it, I'm with you.
I think the problem of having the generated data objects support relations is that all data must be loaded into them. What if you have a long chain of relations between beans/tables. How far do you go? You might end up loading the entire database into the dataobjects, and that would be a pretty nasty performance hit ;-) The way I see it there are two solutions if you absolutely have to do everything in one transaction: 1) Do it the way you're doing it today, with a helper class to establish relationships on the dataobjects. Perhaps XDoclet could generate such classes? 2) Have multiple setData/getData methods accepting different structures of data objects. (Not possible in today's XDoclet). It would be like this: setDataEmployeeOnly( EmployeeData d ); setDataEmployeeAndDepartments( EmployeeData d ); setDataEmployeeAndDepartmentsAndProjects( EmployeeData d ); Likewise for getters. It seems like a difficult one to implement if you ask me. Am I making any sense at all? Aslak >From: "Glenn R. Kronschnabl" <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] >Subject: Re: [Xdoclet-user] Data Objects and CMR >Date: 13 Dec 2001 11:32:45 -0600 > >I wonder if this is "the right way". If you use EJBLocal's without >dataobjects via JSP/taglibs, what transaction type do you use? If you >use "required" on each of the fine grained getter methods, each fine >grained get method will result in a database read/write. If you use >"supports" then the result is vendor specific. Under weblogic, an >unspecified tx results in a local tx on the entity bean, again, a db >r/w. > >Given the performance hit, I think we're always going to need value >objects... unless I'm missing something or I don't understand tx's. > >Glenn > >On Thu, 2001-12-13 at 07:40, rinkrank clob wrote: > > My understanding of the EJB 2.0 spec is that remote entity beans are > > "deprecated". You should only use local entity beans. > > > > Data objects were invented mainly to avoid calling remote entity beans >and > > reduce network traffic. Therefore, if remote entity beans are not used, >I > > don't see the reason to use data objects either. Just use the local >entity > > beans (which have the CMR support, right?). > > > > In other words, my understanding of EJB 2.0 is that data objects go down >the > > drain with remote entity beans. You'll never need them again. Would this > > work for you? I know you're a local-fan ;-) > > > > My 2 cents on J2EE patterns ;-) > > > > Aslak > > > > >From: "James Higginbotham" <[EMAIL PROTECTED]> > > >To: <[EMAIL PROTECTED]> > > >Subject: [Xdoclet-user] Data Objects and CMR > > >Date: Wed, 12 Dec 2001 20:23:28 -0600 > > > > > >Anyone out there using CMP 2.0 and container managed relationships >(CMRs) > > >with XDoclet? How are you handling the data objects being generated >without > > >relationships? My guess is that I would write a simple class to wrap my > > >master and detail objects, but this somehow seems wrong. > > > > > >For example, I have a UserAccountData, UserPhoneData, and >UserAddressData. > > >Right now, it is a 1-1 mapping, so I would create a UserAccountModel, >which > > >held 1 reference to an instance of each. My stateless session bean >would > > >then accept the model in its createAccount() method and create the 3 >CMPs > > >appropriately. > > > > > >Anyone have any suggestions on this? > > > > > >Thanks, > > >James > > > > > > _________________________________________________________________ > > Get your FREE download of MSN Explorer at >http://explorer.msn.com/intl.asp. > > > > > > _______________________________________________ > > Xdoclet-user mailing list > > [EMAIL PROTECTED] > > https://lists.sourceforge.net/lists/listinfo/xdoclet-user > > > >_______________________________________________ >Xdoclet-user mailing list >[EMAIL PROTECTED] >https://lists.sourceforge.net/lists/listinfo/xdoclet-user _________________________________________________________________ Send and receive Hotmail on your mobile device: http://mobile.msn.com _______________________________________________ Xdoclet-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/xdoclet-user
