[ZODB-Dev] Re: MVCC and packing

Jeremy Hylton jeremy at zope.com
Thu Oct 9 07:22:47 EDT 2003


On Thu, 2003-10-09 at 05:19, Toby Dickenson wrote:
> Ive been thinking about the interaction of MVCC and packing.... The natural 
> implementation in most storages could lead to incorrect behaviour if 
> loadNonCurrent was asked about a transaction that predates the most recent 
> pack.

I think that's right.  Did I forget to mention this in the plan? 

> Is it the responsibility of the storage to check this? 

Yes.  If the transaction specified in loadNonCurrent() has been packed,
then the storage should not return data.  I'm not sure if it should
return None or raise an exception.

Jeremy





More information about the ZODB-Dev mailing list