[tracker1]

yeah, 1-2 across an index is fine... but I've seen live websites with very normalized structures where it took no less than 30 joins to get a flat view of a single resource. I could do the same with about 4 secondary queries (each with several joins), but I was trying to map a mental model of where all the data lived as a single view, so I could extract flat records for a search database.

There was absolutely zero advantage in how the data was structured in that case (auto classifieds website).

That's not to say that database normalization and modest level of joins is always bad... it's just something that can go too far, and holds things back even more in certain environments. FWIW, I started bundling child data in XML before JSON was a thing in highly controlled environments where any schema change was very difficult and required approvals through several groups in a large banking org.

That JSON is fairly well supported today only makes this an easier and better option IMO. Again, sometimes, but enough times to make note of.