Re: Document NULL

v5 Attached, v5-0001 is just v4-0001 rebased; v5-0002 is the rework over
v4-0001. There is no formatting-only patch this round.

Wiki tracker: https://wiki.postgresql.org/wiki/Documenting_NULL#ToDo_Note

On Tue, Dec 10, 2024 at 11:52 AM Jeff Davis <pgsql(at)j-davis(dot)com> wrote:

> On Mon, 2024-12-09 at 15:27 -0700, David G. Johnston wrote:
> This results in falsifying the common-sense
> > notion
> > that "p OR NOT p" is always true.
> > </para>
>
> Thank you.
>
> I might reword the final sentence as more of an example, like: "Unknown
> values can lead to surprising behavior, for instance "NULL OR NOT NULL"
> evaluates to the null value."
>

I went with an example instead.

I got rid of the row counts on the examples and did \pset null NULL for the
newly added example. Then I wrote the part about sometimes NULL is the
empty string and sometimes it is NULL. When I finalize the examples I'm
probably going to \pset null <NULL>.

I'm a bit hung up on the "section" terminology. The automatic naming calls
everything a Section but I'm calling the sect1 the Section, sect2s
Sub-Sections and am rewording things to avoid having to make a choice for
sect3s. Am I overthinking this? Related, right now I have a mix of
Section links and "natural language" links. I'm inclined to make a pass
converting probably everything to "natural language" links - or maybe those
pointing within the same sect1 but leaving outbound links more formal.

David J.