From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
cc: "Strauss, Randy (ARC-AF)[SGT, INC]" <randolph.a.strauss@nasa.gov>,
        "pgsql-docs@lists.postgresql.org" <pgsql-docs@lists.postgresql.org>
Subject: Re: Lack of detailed documentation
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Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Mon, 10 Feb 2020 15:43:40 -0500"
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Date: Wed, 22 Apr 2020 19:36:54 -0400
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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=3Dpostgresql.git&a=3Dcommitdiff&h=3D9=
e2a87b62db87fc4175b00dabfd26293a2d072fa
... sans documentation of course.