I agree with a lot of what you he says, however what about the case of getting 10 rows with 20 columns - each column needing a join. The optimizers often go nuts over this sort of thing, as that's 20! combinations the optimizer must iterate over to get a good join order.

Apparently, Postgres has a genetic optimizer that handles this... curious to see if this is an issue or not.

Incidentally, I'd like to say that I loved the author's Relational Basics II at http://www.revision-zero.org/relational-basics-2 I've come to the conclusion that SQL is particularly limited in its application and implementation. I'd love to see a better declarative language for databases!