On Tue, 4 Jul 2017 at 23:01 Tom Lane <t...@sss.pgh.pa.us> wrote: > I'm pretty sure that that is the model that relational databases (and the > SQL language in particular) replaced, back in the 70s or so. Look up > "network" databases (eg CODASYL) and "hierarchical" DBs (eg IMS) for some > ancient history here. Yeah, you can do it like that, but it's seriously > painful to develop and maintain. People were more excited about spending > human effort to save machine cycles forty years ago than they are today.
Network database programming is, indeed, imperative; but as I understand it there was not much of a planning layer -- the program was the plan. In C#, one has LINQ; and in Scala and Haskell, monadic comprehensions; and even in Python one can overload iteration to allow a translation of imperative syntax to declarative syntax. The goal with these features, is generally to present a familiar interface to an unfamiliar semantics. If we imagine network databases have one layer: Imperative Plan And SQL databases have two: Declarative Query -> Imperative Plan It seems reasonable to say, LINQ, &al. have three: Imperative Syntax -> Declarative Query -> Imperative Plan Fortress is rather the same, since it translates imperative to functional to assembly. Kind Regards, Jason
