In EJB 2.0, they have added local interfaces to address the overhead issue.
Local interfaces are similar to the remote interface except it can't be
remoted, and parameters are not serialized (pass by ref), which is one of
the most expensive parts of a remote interface (other then the wire time).
JBoss, like most EJB servers, has an optimized mode which does not serialize
parameters on remote interfaces, where the objects are collocated in the vm.
So the authors are right in the general sense, but wrong for most EJB
> -----Original Message-----
> From: Ole Husgaard [mailto:osh@...]
> Sent: Saturday, June 30, 2001 1:00 PM
> To: jboss-user@...
> Subject: Re: [JBoss-user] Entity beans and rows in tables
> I think that both these statements are true.
> EJB1.1 CMP says:
> one table row == one entity bean
> And common sense (as well as most experts of
> component oriented development) says that:
> (one table row == one entity bean)
> "no good"
> due to interbean call overhead and no advantage.
> The conclusion is harsh, though obvious:
> EJB1.1 CMP is no good.
> I guess this is why CMP is changed for EJB2.0.
> Best Regards,
> Ole Husgaard.
> bcd@... wrote:
> > >From reading the EJB spec and a number of other documents, I have
> > gained the impression that (one table row == one entity bean) if I
> > want to use CMP.
> > I am currently in the progress of reading the J2EE
> Blueprints, and in
> > a discussion on the cons of using entity beans, the
> following is said:
> > "(...) Therefore modeling every object representing a row in the
> > database as an entity bean is not recommended. An entity bean is
> > better suited to represent a coarse-grained business object that
> > provides more complex behavior than only get and set methods for its
> > fields."
> > (
> in the bullet titled "Representing persistent data", first bullet
> on the page.
> This seems to imply that there is another method that I have not seen
> in which I may not need one entity bean per row.
> Is someone able to elaborate on this?
> Bent D
> Bent Dalager - bcd@... - http://www.pvv.org/~bcd
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