Hi Neophilius,

I think you are referring to a Data Virtualisation solution like Teiid (open source) or Denodo. These allow you to model a layer over disparate sources, so you can query them as it they are a single data source. Commercial solutions can be expensive.

It's all very cool, but this isn't a recommendation, there are lots of things to consider first.

E.g.

Is it overkill for what you need?

Would the latency for querying remote databases be acceptable?

Time zones: would you need to live query during their overnight batch windows etc?