[ZODB-Dev] mvcc related error?

Chris Withers chris at simplistix.co.uk
Tue Mar 20 09:15:25 EDT 2007

Dieter Maurer wrote:
> Chris Withers wrote at 2007-3-16 08:45 +0000:
>> ...
>> Is there any way an object could be invalidated without there being a 
>> non-current revision to read?
> Sure (through a call to "ZODB.DB.DB.invalidate"), although usually
> it is done only after the object changed.

OK. I'm still not clear on whether what you describe is a bug or simply 
what might happen now?

> We are using it to cause objects to be flushed from all
> ZODB connection caches (because we know that their "_v_" might
> contain an inconsistent state).
> Fortunately, we did not yet met the "loadBefore" problem you have hit.

Oh, so it's just me who's lucky? ;-)

>> What are the possible causes of invalidation?
> A change of the object or some explicit call for invalidation.

I don't think any explicit calls are involved here...



Simplistix - Content Management, Zope & Python Consulting
            - http://www.simplistix.co.uk

More information about the ZODB-Dev mailing list