I’m not sure I agree with the notion that Data Scientists need to be able to understand data coming from ‘different sources’.
I still believe that DataMart and SQL Server Analysis Services should hide most of that complexity from nearly *ALL* the other employees. Otherwise it just comes down to having ‘one version of the truth’.
If a company cannot make good solid decisions in the planning of their infrastructure.. I just don’t see the point of having a half dozen types of database technology at every company.