Re: [xml-dev] Is CVS A Practical Means to Manage XML Versions InA Produc

["Johannes.Lichtenberger" <Johannes.Lichtenberger@uni-konstanz.de>]

On 09/19/2011 04:15 PM, Ghislain Fourny wrote:
> Hi Andrew,
> 
> Sure. In the XML Time Machine, the XDM (data model) is augmented with an additional dimension: time. This means that a node (in the XDM spacetime) is identified with two coordinates:
> 
> 1. a reference URI
> 2. a version URI
> 
> The reference URI corresponds to the concept of node identity in the XDM specification. A node that evolves according to the XQuery Update specification (meaning that its accessors are modified, e.g., children added/removed, node renamed) corresponds in the XML Time Machine to a series of nodes that share the same reference URI, but have different version URIs. Such a series of nodes is called a node timeline.
> 
> Using time axes means navigating within a timeline. Given a node in version 10, it is possible to get the "same" node in version 5. The concept of node identity in the XDM specification allows to give a meaning to "same".
> 
> Does it make sense?

Yes, we are using a revision/nodeKey tuple whereas the nodeKey is always
stable through the revisions, which seems to be the equivalent to the
URIs approach. I'm currently implementing some temporal axis which just
open the appropriate revisions within an Iterator/Iterable (Java).
Though I'm currently thinking about some implementation facets.

best regards,
Johannes