Part 2 ended with a line from Diego: “Time travel runs forward too. Retroactive bookings, planned prices, scenarios for the future.” That's exactly where we pick up now.
The 1st Part finished with a promise: for two timelines to interlock cleanly, their time periods have to be brought into a clear relationship with one another. That mechanism is what we look at now.
There's a question that comes up in every workshop sooner or later: “Do we really need this complexity?” What people mean is bitemporal historization – two timelines instead of one, a few more columns, more logic when loading. It's a fair question.
Or the battle announcement of the incoming interface
The BI Center of Competence (CoC) has decided to use bitemporal data storage when setting up a new data warehouse for one of the business units of the fictitious company FastChageCo™.
BI CoC is well advanced in the bitemporal implementation of Data Vault database objects as well as loading patterns. The already connected systems via formally defined incoming interfaces have worked without problems so far.