SQL, or rather the relational model, is great for what it does. A thorough knowledge of both is central to most of what I've done over the last many years. But

SQL, or rather the relational model, is great for what it does. A thorough knowledge of both is central to most of what I've done over the last many years. But there are places where you don't really want named attributes with the names known beforehand, you want to generate new attributes, perhaps named on the fly, perhaps designated ordinally. The relational model doesn't really have room for this. The various flavors of SQL offer bolted-on ways to do this, incompatible & quite different. But it's a living...