[ZODB-Dev] Re: MVCC and packing

[Dieter Maurer]

Jeremy Hylton wrote at 2003-10-9 07:22 -0400:
 > 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.

In my implementation, it raises a "ReadConflictError".


Dieter