As far as I recall, a lot of the conversion of the mixed Python/SQL code was done by devs that certainly aren't SQL experts (although it was then reviewed by more experienced devs so that improvements could be suggested to the new SQL code), so either the code wasn't that difficult to understand, or at least the Python parts of it wasn't.

But in general, if you run into an SQL query that is difficult to understand (for sure some of them in hivemind are), I strongly recommend using an AI to comment the code for you, it does a good job.