Love the article and concept of the narrow waist. The structure and familiarity of SQL seems powerful and practical as you describe it. As a non-database-expert (to say the least), I’ve always been skeptical of SQL because of the forced structure it placed on data given its constraints. This probably sounds ignorant from your vantage point. But I’m wondering: what do we lose in a SQL world when it comes to flexibility? If everything has to fit through that narrow waist of SQL, what are we giving up?