Field value history on objects in CDF.

Hey, 

Currently, it’s hard to maintain a coherent versioned datamodel in CDF. With Templates, and further developments there, this becomes easier.

Even with a versioned datamodel it seems to me that there still isn’t a good way to track changes in the model that are not version-breaking.

In our datamodel we have two types of changes that we would like to track in a structured way: 

1. Field value updates, as simple as a metadata field and as complex as the unit-multiplier on a TimeSeries changing.
2. Edge field value updates. Our model is  an adption of a RDF representation of  a Common Information Model in the Common Grid Model Exchange Specification for Norway. A field on an object can imply an edge in the datamodel, and this field can change. Currently this is solvable with  Labels and Start/End time on Relationships today, though it isn’t obvious that we would want to introduce an Edge type to Templates?

This question is a part of the larger struggle of maintaining a sane structure on a time-dependent datamodel. In effect you end up maintaining two or three versioning systems on top of each other: the version of the source datamodel(s), the version of the interface(s) between these models, and the version of your representation(s) of the source datamodel(s).