[Zope-dev] ZODB3 - updated stored objects

R. David Murray bitz@bitdance.com
Tue, 23 May 2000 13:03:25 -0400 (EDT)


On Tue, 23 May 2000, Thomas Weholt wrote:
> will be stored in a new location with the updated values? If so, isn`t that
> kinda dumb, at least if there`s no way to override this "feature"? Anyhow, I
> want to store several big custom objects in ZODB. These objects can be
> frequently updated, and I`d like to update the previously stored object, not
> store the entire thing again. 
> 
> Can anybody clarify or give me hints on how to do this?

Sounds like you are a perfect candidate to beta test the mountable
storage code that we hear is soon to be released into the CVS,
which is an option I forgot to mention in the other note.  This
should allow you to use some storage other than the ZODB to back
your large dynamic objects, but still use the ZODB and its undo
support for the rest of your site.

You don't want to be able to override the 'append to modify' feature
of the regular ZODB because that is part of the source of its
high stability.  The system can crash in the middle of a transaction
and the ZODB is guaranteed to be in a consistent state becuase the
only changes to the file are the appends at the end of it.

--RDM