> I really do not think it’s a difficult language to learn.
Neither do I, but there's huge distances between "spend-an-afternoon-intro-on-it" and "learn-it-well-enough-for-occasional-work" and "learn-it-enough-to-build-serious-databases".Of course, everyone in HN is "advanced" so what do I know!
> learn-it-enough-to-build-serious-databases
This is more about infrastructure than SQL though. You don't need to know any fancy SQL to do streaming replication or whatever, for instance.
You're correct that being good at Managing Data is a complex domain with a lot of gnarly bits, but I was talking about Writing SQL being fairly easy