I completely agree. In an EJB environment, the dB should manage the cache. Any
cache above that level is at best useless and at worst problematic.
I have yet to find a CMP implementation that is useful/useable. I'm not sure
that I even want or need CMP.
"Beauchemin, Bob" wrote:
> As long as the subject has been brought up, what is anyone's opinion on
> Persistence Power Tier? They make some amazing claims and seem to have
> addressed most of the CMP concerns like facade pattern, data chunking,
> stored procedure utilization, relationships, cache management and failover.
> Opinions? War stories? The patent for parts of the architecture is on file
> and accessible through the web and makes interesting reading.
>
> IMHO, CMP entity beans don't seem all that useful without a cache
> architecture to make it worthwhile to shuttle all that data back and forth
> between database and middle tier, with the gobs of network roundtrips that
> implies. Unless the EJB container has a better SQL engine than the RDBMS or
> 90% of the access is row-at-a-time (and, pre-relationship support,
> table-at-a-time). Am I missing something obvious? Or are performance and
> scalability not major concerns?
>
> Bob Beauchemin
> [EMAIL PROTECTED]
>
> -----Original Message-----
> From: Chip Wilson [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, December 20, 2000 1:48 PM
> To: [EMAIL PROTECTED]
> Subject: Re: O/R Mapping Tools
>
> I've used it on three different projects. I don't have the ability to
> support all the following claims right now - so take them for what they are;
> unsupported opinions. TOPLink is bloated, overly-complex, and innapropriate
> for an EJB architecture. The transaction API and implementation have to be
> shoe-horned into a JTA environment. It doesn't support 2PC, or at least it
> didn't a year ago. Debugging problems is a nightmare. Developing and
> maintaining mappings takes longer than writing individual broker/mapper
> classes for each persistent object. The ramp-up time for developers is
> extremely long. TOPLink is really, really slow. The cache is useless in an
> EJB environment. TOPLink is really expensive.
>
> I have written, helped write, designed and used countless O/R frameworks in
> C++, Smalltalk and Java. I even helped develop a commercial competitor to
> TOPLink, but it is no longer supported.
>
> In an EJB environment, I favor a minimalistic O/R framework with
> broker/mapper classes that execute JDBC calls and map between the schema and
> the domain model. Entity beans access the persistence framework through a
> facade. I typically prefer to hard-code the mapping logic, as this is the
> easiest to develop, learn and maintain. If you must do some sort of
> meta-data-based mapper, keep it simple and allow the ability to do it
> manually in specific brokers. A simple framework like this can be designed,
> implemented and tested (minus all the individual broker classes) in 40
> man-hours.
>
> >From: "B. Flaumenhaft" <[EMAIL PROTECTED]>
> >To: [EMAIL PROTECTED], [EMAIL PROTECTED]
> >Subject: Re: O/R Mapping Tools
> >Date: Wed, 20 Dec 2000 11:55:20 -0800
> >
> >
> >Can you give us some details? I'd be very interested to learn more. I
> >looked at TOPLink some time ago and was very impressed by its feature
> >set and customizability. It was simply too expensive, and I had some
> >doubts about performance and the runtime model.
> >
> >Why should we run away?
> >
> >Thanks,
> >Ben Flaumenhaft
> >
> >At 8:13 AM -0600 12/20/00, Chip Wilson wrote:
> >>Run away from TOPLink as fast as you can. Run far away.
> >>
> >>>From: Thomas B�kamp <[EMAIL PROTECTED]>
> >>>Reply-To: A mailing list for Enterprise JavaBeans development
> >>><[EMAIL PROTECTED]>
> >>>To: [EMAIL PROTECTED]
> >>>Subject: O/R Mapping Tools
> >>>Date: Tue, 19 Dec 2000 23:37:50 -0800
> >>>
> >>>Hi,
> >>>
> >>>Parts of my current work is to evaluate O/R Mapping Tools products. Is
> >>>there
> >>>such a thing a report to study different O/R Mapping Tools . Currently we
> >>>are looking at Cocobase and Toplink. Can somebody help with the following
> >>>questions:
> >>>
> >>>- Anybody know about Cccobase or Toplink the quality and Performance?
> >>>- Any other O/R Mappers worth evaluate? Especially we would like to know
> >>>if
> >>>there is a product that the C++-part of the project can use too.
> >>>
> >>>Thanks in advance
> >>>
> >>>Thomas.
> >>>
> >>>_________________________________________________________________________
> >>>Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
> >>>
> >>>=========================================================================
> ==
> >>>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".
> >>>
> >>
> >>_________________________________________________________________
> >>Get your FREE download of MSN Explorer at http://explorer.msn.com
> >>
> >>==========================================================================
> =
> >>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".
> >
> >
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com
>
> ===========================================================================
> 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".
>
> ===========================================================================
> 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".
===========================================================================
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".
