I would say focus on what's fundamental and pragmatic to each (e.g. immediately relevant). All the recent stuff actually isn't that, unless you're the one doing

I would say focus on what's fundamental and pragmatic to each (e.g. immediately relevant). All the recent stuff actually isn't that, unless you're the one doing the research or implementing them. I think LSMs are great and I'd gladly use a db that uses them but I don't need to know how they work, only their properties when selecting a db. If I'm using a relational DB though I'd damn-well better know how indexes work.