[ZODB-Dev] Historical revisions in ZODB

[Chris Withers]

Dieter Maurer wrote:
> I will implement "edition"s for HCFileStorage.
> 
>   The base concept it an object "HistoryReference" that
>   references an object (identified by an "oid") at a given
>   time (identified by "serial"). Packing will not release
>   records when they are directly or indirectly referenced
>   by a "HistoryReference".
>   This will make packing more expensive. I expect a 50 % increase
>   in time and memory.
> 
>   An edition is a collection of "HistoryReferences", effectively
>   freezing the state of objects referenced from the edition
>   at a given time. The "HistoryReference" mechanism protects
>   this state against packing.

It would be very cool to see this in the default FileStorage implementation...

cheers,

Chris