Hi I just want a few precisions about this mail.
Can you explain the fact that ODMG API removes object from the cache at
transaction commit, because I'm facing the same problem and I can't
explain to myself this fact, or if it is hard to explain can u throw
some resources or links


Thx in advance

Le sam 04/01/2003 � 10:29, Thomas Mahler a �crit :
> Hi David,
> 
> [EMAIL PROTECTED] wrote:
>  > Here is my problem.  I have the following model (0.9.8, single VM)
>  >
>  > A contains a B.
>  >
>  > I have the following data.
>  >
>  > A1 containing B3 and A2 containing B3
>  >
>  > A1 and A2 are loaded (so they should be in the cache) B3 shoud also
>  > be in the cache.
>  >
>  > I update A1.
>  >
>  > I load A1 and A2.
>  >
>  > At this point, it appears that: A2 came from the cache A1 did not
>  > come from the cache. The B pointed to by A1 and A2 are no longer the
>  > same B (== fails, to put it in Java terms)
>  >
> 
> Even if your app is not running as an ODMG app, it is not generally safe 
> to check for == !
> The cache could also be cleared ba a garbage collection and thus could 
> enforce reloading.
> 
>  > It appears that updating A1 has flushed A1 and B3 from the cache?
>  >
>  >
>  > Is this correct behavior?
>  >
> 
> Currently the ODMG API removes all objects locked to a tx from the cache 
>   on commit().
> This is done to preserve proper tx isolation.
> 
>  >
>  > ObjectEnvelopeTable.commit() contains the following.... command line
>  > of code... // in a distributed environment all broker caches must
>  > invalidate the Object broker.invalidate(new Identity(mod.getObject(),
>  >  transaction.getBroker()));
>  >
>  > However, it appears that the singlevm is flushing the object from the
>  > cache also.
> 
> Correct! There had been long discussion on transactional isolation with 
> ODMG and I wanted to be on the safe side!
> The new OTM layer will provide a more intelligent cache management.
> 
>  > Personnally, I would really rather not have objects removed from the
>  > cache just because I update them.
>  >
> 
> I agree, this does make no much sense in singlevm mode!
> If you are preparing a fix I will commit it to CVS !
> 
> cheers,
> Thomas
> 
>  > This is causing me a problem, because I go and load "bunches of A's",
>  > and some come from the cache, and some do not, which means the B's
>  > are "who knows what", and I'm trying to build a "complex" internal
>  > data structure, but when B is inconsistent, thinks don't work well.
>  >
>  > Thanks David Corbin
>  >
>  >
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