[gf000]

Well, you have basically implemented a Java type-system level type checker for SQL. I don't believe there is any type system strong enough to express the whole thing without the escape hatches (casts), besides Lean, Coq and alia.

[lukaseder]

Not sure what you mean. I meant that without declaration site variance, ("pragmatic") unsafe casting is everywhere in jOOQ's internals. Without being able to capture wildcards in local type variables, ("pragmatic") rawtypes are everywhere as well (check Collections.swap() for an illustration)