[ZODB-Dev] non-transactional undo

[Chris Withers]

Tim Peters wrote:
> I believe that every time a transaction is committed to a FileStorage, a
> status byte in a header gets rewritten at the end of the write (to say that
> the write completed successfully).  In particular, if you make a copy of a
> live FileStorage, the last transaction copied may be in an incomplete state
> because of this.

When would that not be acceptable?

>>so the possibility of a non-transactional undo complicates any backup
>>schemes.
> 
> Correct backup schemes involving a live storage are likely complicated
> regardless.

What concerns make it complicated?

cheers,

Chris