| > It looks very important, popular and well established, but what is it? It's easier to explain what Cube is if we first define what the Semantic Layer(SL) is. In a few words, the SL is the abstract representation of business objects, for example: sales, users, conversion rates, etc. Cube provides the language to define the SL, an API to access it, access control mechanisms and a caching layer. It's important to emphasize that Cube is a stand-alone SL, decoupled from any BI visualization tool. That's the "headless" part, and I would also add that is "feetless" since it supports multiple source DBs. Looker the other big name in the space has the incentive of selling you more usage of BigQuery and of locking you in with their UI, it just recently started to open up to the idea of APIs. The idea is that you have a central place where you define the SL and then you don't need to duplicate the definition on every downstream application, which may lead to errors or inconsistencies. > Is it that it can perform a single query across multiple databases? Cube allows you to join data from multiple databases at the caching layer, that's fundamentally differently than a federated query engine. But from the downstream application perspective it has the same outcome. By being done at the caching layer it has inherent advantages and limitations vs federated queries. I really like these series of articles by David Jayatillake that go into deeper detail: 1. https://davidsj.substack.com/p/semantic-superiority-part-1
2. https://davidsj.substack.com/p/semantic-superiority-part-2
3. https://davidsj.substack.com/p/semantic-superiority-part-3
4. https://davidsj.substack.com/p/semantic-superiority-part-4
5. https://davidsj.substack.com/p/semantic-superiority-part-5 |