Re: Lack of detailed documentation

I wrote:
> One thing that's sort of blocking any real progress on this is the
> draconian space constraints imposed by the tabular format, which is
> hurting us on a lot of these pages, not just this one.  Alvaro did
> some preliminary investigation towards finding a better way,
> but nobody's tried to push that forward.

I've been making an attempt to improve that situation, and along
the way just pushed an expansion of the geometric-operator docs:

https://www.postgresql.org/docs/devel/functions-geometry.html

There's probably still some things to be desired, but it's a lot
less fuzzy than before.

One thing that surprised me is that I couldn't find any well-known
name for what the * and / operators are doing; digging around on
the net and in some dusty old math textbooks didn't yield any exact
matches.  I ended up adding footnotes with the actual computations,
but I'm not very happy with that approach.  Surely Lockhart[1] got this
definition from someplace, though, and didn't invent it out of thin air.

            regards, tom lane

[1] I'd supposed we could blame this stuff on Berkeley, but excavation
in our git history shows it came in at
https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=9e2a87b62db87fc4175b00dabfd26293a2d072fa
... sans documentation of course.