Reading the sections 2.2.3 (about joins) and 3.5 (about code comprehension) took me aback! I came with a positive a priori for dataframes, but changed my mind.

Reading the sections 2.2.3 (about joins) and 3.5 (about code comprehension) took me aback! I came with a positive a priori for dataframes, but changed my mind. SQL is far to be perfect, but at least there are sound foundations!