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From Andrus Adamchik <and...@objectstyle.org>
Subject Re: Imports
Date Sun, 09 Mar 2008 17:45:46 GMT
BTW, if there's no commit or rollback, and the transaction stays open  
indefinitely, this would result in quick connection pool exhaustion.  
So why would you do that?

Andrus


On Mar 9, 2008, at 7:19 PM, Andrus Adamchik wrote:
> This could be a DB artifact. E.g. with MySQL MyISAM tables. Which DB  
> are you using?
>
> Andrus
>
> On Mar 8, 2008, at 5:53 AM, Malcolm Edgar wrote:
>
>> I have been playing around this in a web context, and what I am
>> finding with a user created Transaction, if the DataContext commits
>> the changes, unless the Transaction explicitly performs a rollback  
>> the
>> changes will be committed to the database.
>>
>> This is not what I was expecting, but I am wondering if this is an
>> artifact of the thread pool, ie maybe the same thread is coming back
>> of the pool.
>>
>> regards Malcolm Edgar
>>
>> On Tue, Feb 19, 2008 at 8:31 PM, Malcolm Edgar <malcolm.edgar@gmail.com 
>> > wrote:
>>> Great! Thanks for that.
>>>
>>> regards Malcolm Edgar
>>>
>>>
>>>
>>> On Feb 19, 2008 11:18 AM, Andrus Adamchik <andrus@objectstyle.org>  
>>> wrote:
>>>> Just use your own transactions, then 'commitChanges' turns into  
>>>> 'flush':
>>>>
>>>> http://cayenne.apache.org/doc/understanding-transactions.html
>>>>
>>>> Andrus
>>>>
>>>>
>>>> On Feb 18, 2008, at 7:49 AM, Malcolm Edgar wrote:
>>>>
>>>>> Hi Ari,
>>>>>
>>>>> thanks for the response.  This would be a very good 3.0 feature  
>>>>> if it
>>>>> is not already present.
>>>>>
>>>>> In Hibernate this functionality is performed as a flush operation,
>>>>> where CRUD operations are performed against the transaction but  
>>>>> are
>>>>> not actually committed.
>>>>>
>>>>> Would this would cause issues with Cayenne PK generation  
>>>>> strategy, are
>>>>> the highest/last table id values they maintained in memory?
>>>>>
>>>>> regards Malcolm Edgar
>>>>>
>>>>> On Feb 18, 2008 3:16 PM, Aristedes Maniatis <ari@ish.com.au>  
>>>>> wrote:
>>>>>>
>>>>>> On 18/02/2008, at 2:07 PM, Malcolm Edgar wrote:
>>>>>>
>>>>>>> Is there a way in Cayenne, possibly using Transactions, that
 
>>>>>>> we can
>>>>>>> perform this import, do inserts and queries against the  
>>>>>>> transaction
>>>>>>> and only commit/rollback at the end?
>>>>>>
>>>>>> Subclass the Cayenne context, override performQuery and add in  
>>>>>> your
>>>>>> own custom code there to look for new objects within the context?
>>>>>> There is almost certainly a way to have a database transaction  
>>>>>> cross
>>>>>> several Cayenne commits as well, but I can't assist there.
>>>>>>
>>>>>> In fact we've done this several times in our application and I  
>>>>>> was
>>>>>> just thinking the other day whether this might be an option in  
>>>>>> a new
>>>>>> generified performQuery and might be useful to be pushed into
>>>>>> Cayenne.
>>>>>>
>>>>>>
>>>>>> Ari Maniatis
>>>>>>
>>>>>>
>>>>>> -------------------------->
>>>>>> ish
>>>>>> http://www.ish.com.au
>>>>>> Level 1, 30 Wilson Street Newtown 2042 Australia
>>>>>> phone +61 2 9550 5001   fax +61 2 9550 4001
>>>>>> GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49  
>>>>>> 102A
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>
>


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