Django - Reversion and South - How to update past revisions while updating a model?

I would like to preserve past revisions of MyModel instances, while updating and migrating My开发者_StackOverflow中文版Model with south.

Is it possible to update the past revisions?

Is it necessary to update the revisions on all types of changes to the model?

What kind of changes, if any, will force me to erase the revision history no matter what?

Is there an elegant way to automate the revision updating process?

As i posted on the related github issue posted by filipe, using a "schemaless" database like couchdb is probably the way to go, when you want to version schemas+data elegantly.

Doing automatic model transformations on schema transformations is surely posible, but my experience is that schema transformations alone are fragile and require a lot of care and testing.

there are quite a lot of nosql databases outthere, and deciding if couchdb or hbase or [insert your nosql database of choice] is ok for your needs will depend a lot on your use case.

Although I don't have a definite answer, this thread might give you some hints: https://github.com/etianen/django-reversion/issues/50