On Feb 28, 2007, at 12:50 PM, Jacek Laskowski wrote:
On 2/28/07, Lasantha Ranaweera <[EMAIL PROTECTED]> wrote:
For the JPA side I think now we need not hard coded openjpa JPA
provider
class name. Am I correct David (Is there any situations where
both CMP
and JPA comes together)?
As far as I understand the spec, ear can contain CMPs and JPA
entities. It's not recommended that CMPs and JPAs are mixed together
in one jar file, but it's very legitimate to have them separated in
two jars bundled in one ear (I'd be glad if someone - perhaps one with
leading 'D' in his first name, could verify my understanding, though
;-)).
That is the standard recommendation, but doesn't hold for Geronimo or
OpenEJB. The reason that experts recommend this is because normally
the CMP and JPA are separate persistence systems. This means that
you have two separate caches, locks, flush semantics and so on, so if
you are not careful you can corrupt your database. In OpenEJB we
chose to use JPA for the CMP implementation, which means you only
have one system with two views, so you in general don't have the
perviously mentioned problems.
-dain
