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From Jörg von Frantzius <joerg.von.frantz...@artnology.com>
Subject Mixture of optimistic and pessimistic transactions?
Date Wed, 05 Apr 2006 21:27:46 GMT
Hello,

as it is possible to switch transactions between optimistic and 
pessimistic during runtime, there could theoretically be one pessimistic 
and one optimistic transaction updating the same table at the same time. 
The optimistic one would then rely on the pessimistic one to also update 
any version information.

Is this scenario supposed to be supported by the spec?

We have mappings for version information, but we currently run only 
pessimistic transactions. JPOX always updates version information when 
it is mapped in the metadata, be it within an optimistic or pessimistic 
transaction, supporting the above use case. The updating of the version 
information causes high probability of database deadlocks for us, 
though, so I wonder if the version information really must be updated in 
pessimistic transactions. And yes, we could also remove version 
information mapping from the metadata.

Thanks for any hints,
Jörg

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