[wpietri]

> Mapping objects to tables is a solved problem.

Sure, but that's just the standard solution that hides the mismatch. The mismatch is still there. Which is why when performance becomes an issue, there's a whole bag of tricks for tuning the ORM or just sidestepping it and writing a sane query. It's also part of why the SQL database went from the only thing people could conceive of using to one tool among many for data persistence.

As 1970s paradigms go, SQL has had a good run. But the main problem it solves, easily finding and changing your data somewhere on a small number of spinning metal disks, is just not the central problem of computing that it was for a few decades.