[ZODB-Dev] Fixing POSKeyErrors :-)

[Binger David]

On Feb 14, 2008, at 9:43 AM, Jim Fulton wrote:

>> On the other hand, it seems
>> clear that cross-storage references make the system as a whole
>> (software + people) less reliable.
>
> I don't agree in general.

Uh.  I thought we were talking about reported POSKeyErrors that would  
not exist
if there were no such thing as cross-storage references.  I don't  
understand
what there is to disagree with here.  Are you saying that cross-storage
references reduce the risk of other application-breaking conditions?

>
>> Perhaps I misunderstand, but low-level cross-site references seem  
>> like "secret"
>> weakrefs.  Maybe we'd be better off if they were explicit, higher- 
>> level objects,
>> used and dereferenced intentionally where required.
>
>
> I don't object to this approach. I'll note that we had an approach  
> like this before for Zope (mounts) and it had plenty of  
> disadvantages of it's own, including injecting Zope-specific code  
> into ZODB.
>
> If someone can make something like this work without modifying  
> ZODB, I won't object.

Right.  There is no reason for this approach to involve ZODB at all.
If broken "references" must be tolerated, I'm suggesting that they  
should be dealt
with in application/Zope-level code, not in ZODB.

>
> I think it would be easier to make the current multi-database  
> approach a bit more explicit.  I'll probably do that.

Explicit is good.