Hi all - I’m attempting to draw up a Data Vault model for the first time using MS Visio. I have almost a decade of experience with star schemas and just finished reading Dan L’s DV 2.0 book however I’m still trying to get my head around the basics of determining what is supposed to go into my Satellites (Hubs appear to be fairly obvious).
I’ve created a very basic example that represents my problem…
The first diagram shows a very simple star schema of a fact table for an insurance claim:
The second diagram, shows my attempt at modelling this using a Data Vault approach:
The thing I’m really not sure about is the level of granularity / division best appropriate for the satellite/s. In Dan L’s DV 2.0 book for the airport example, it appears that he’s put virtually every possible attribute into their own Satellite however there’s couple of things about this approach that have me slightly stumped (as per my own diagram):
– Where would $$ amounts and business transactional milestone dates typically go? Especially in regards to my own example. As these aren’t what you’d classify as “attributes” or dimensional objects in a regular star schema; they are transactional.
– In DV 2.0, is there a clear best practice way to model / store attributes vs. transactional values (e.g. business dates, cost amounts / payments)? Are these treated differently?
Any feedback and even draw-ups / diagrams in response would be hugely appreciated (as I’m just trying to get my head around the basics first before going deep into building a large model).