3.0.0-SNAPSHOT

On Sep 27, 2012, at 8:37 AM, Dan Tran <[email protected]> wrote:

> Brian
> 
> What karaf version are you using?
> 
> Thanks
> 
> -D
> 
> On Wed, Sep 26, 2012 at 11:37 PM, Dan Tran <[email protected]> wrote:
>> See my comments inline
>> 
>> On Wed, Sep 26, 2012 at 10:05 PM, Brian Topping <[email protected]> wrote:
>>> Dan, I went through a lot of this recently with OpenJPA.  YMMV with other 
>>> providers.
>> 
>> Brian, thank you for sharing this experience, it is surely settle our
>> headache a bit!!
>> 
>>> 
>>> 1. OpenJPA doesn't seem to manage very well with base classes across bundle 
>>> boundaries.  It looked like there needed to be more magic in place that it 
>>> could deal with not being able to enhance or otherwise modify the 
>>> superclass jar due to classloader isolation.  I did set up build time 
>>> enhancement but it didn't seem to be enough and I forgot where I was in the 
>>> code that it was a problem.  One solution to this *may* be to use fragment 
>>> hosts.  For now, we've just duplicated the base classes across the 
>>> persistence bundles, kicking the can down the road a bit.
>>> 
>> 
>> This would mean all your duplicate base classes have their own java
>> package to prevent collision?
>> 
>>> 2. I have been successful in having multiple persistence units in the same 
>>> Karaf runtime and sharing a single data source, but the PUs do need to be 
>>> named differently.  We have noticed some race conditions that occur, 
>>> turning on JPA logging seems to bury them a little deeper, and we haven't 
>>> had time to explore what's going on so we can report it.
>> 
>> This is worry some. Are you able to bring your JPA into production
>> with this issue?
>> 
>>> 
>>> 3. One of the issues with multiple PUs is you need to set them up with 
>>> different names for the sequence tables under DBs like Postgres and Oracle. 
>>>  This can be done statically from persistence.xml.
>>> 
>>> I'm very interested in resolutions to these issues and would like to 
>>> contribute to them, but have been under a lot of pressure with client 
>>> deadlines.  I wonder if others have seen any of these issues yet and can 
>>> offer any better advice than this.
>>> 
>>> Cheers, B
>> 
>> Thanks
>> 
>> -D
>> 
>> 
>>> 
>>> On Sep 26, 2012, at 9:01 PM, Dan Tran <[email protected]> wrote:
>>> 
>>>> Hi,
>>>> 
>>>> I am porting a set of JPA moduels under spring to Karaf JPA where I
>>>> have i module which contains abstract entity classes, and a couple of
>>>> other JPA modules use the 'base module', is it possible under
>>>> jpa/openjpa/derby??
>>>> 
>>>> I am struggling on what do do with the base module since it has no
>>>> entities, what the persistent.xml looks like, should it has its own
>>>> persistent unit?
>>>> 
>>>> Can all three modules use the same persistent unit name?
>>>> 
>>>> any suggestion is greatly appreciated.
>>>> 
>>>> thanks
>>>> 
>>>> -D
>>> 

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