This is not implied by the lifecycle description in section 9.3. An entity,
once activated, may go through many calls to ejbLoad, ejbStore, and various
business methods in various transaction contexts before it is passivated and
dissociated with its identity.
> -----Original Message-----
> From: Andreas Vogel [SMTP:[EMAIL PROTECTED]]
> Sent: Friday, May 14, 1999 8:07 AM
> To: [EMAIL PROTECTED]
> Subject: Re: EJBs and the internet
>
> Robert,
>
> you need to look carefully at the life cycle definition for entity beans.
> An entity
> in the pool is not associated with any data. The association happens at
> the begin of
> a transaction, that is ejbLoad(), at the end of the transaction the data
> is written
> back into persistence storage (ejbStore()), the entity returns to the pool
> and looses
> the association with the data. The next client goes through the same
> cycle. The
> advantage of the approach is data integrity, the disadvantages is
> performance
> overhead. A container may do clever things when CMP is used.
>
> Cheers,
>
> Andreas
>
> Robert Krueger wrote:
>
> > Andreas Vogel wrote:
> >
> > >
> > > Entity beans are specifically targeted towards transactions. Caching
> is a value
> > > add of CMP implementation BMP prevents you from caching.
> > >
> >
> > Why would that be? I thought a container could keep entity bean data in
> > memory no matter if CMP or BMP? My understanding was that say client 1
> > requests an entity bean instance with PK x which is not in main memory.
> > It is retrieved from the DBMS (CMP or BMP) and instantiated in main
> > memory. Then client 2 also requests the entity with PK x, which then may
> > still be in main memory. Where is the difference between CMP or BMP
> > here? It may very well be that I'm misunderstanding the spec as I am not
> > an expert. Could you please enlighten my on that point as it seems to be
> > a very important factor in designing an EJB application using entity
> > beans with BMP with acceptable performance.
> >
> > Thanks,
> >
> > Robert
> >
> > --
> > (-) Robert Kr�ger
> > (-) SIGNAL 7 Gesellschaft f�r Informationstechnologie mbH
> > (-) Br�der-Knau�-Str. 79 - 64285 Darmstadt,
> > (-) Tel: 06151 665401, Fax: 06151 665373
> > (-) [EMAIL PROTECTED], www.signal7.de
> >
> >
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> --
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