"David G. Johnston" <david.g.johnston@gmail.com> writes:
> I agree the material in Extending SQL - SQL Functions, plus normal
> expectations, mean that we do indeed cover the topic sufficiently. The
> location and specifics of the material and use of cross-references could
> use some attention though its also not an area that gets too many questions
> so people are figuring this all out one way or another (or not finding a
> need and just don’t know what they are missing…)
Yeah, there is a lot of material in that chapter that is about using
functions, not just writing them. I don't think anyone's entirely
happy about the current factorization of those parts of the manual;
but it's not entirely clear how to make it better, either.
regards, tom lane