Re: Document NULL

On Fri, Jan 17, 2025 at 6:41 AM David G. Johnston
<david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
>
> Yeah, I did spell check but not a grammar check. These weren't spelling errors though. Anyway, good point running the resultant web page through chatgpt or grammar-aware program.
>
> I still need to put together the example changes in these last couple of suggestions. The attached v6 omits those and the indenting - and I've consolidated it back into a single patch.
>
hi.

<title>Array Elements and IN Bag Members</title>
google "Bag Members" didn't yield any relevant results.
there are two appearances of "bag" in doc/src/sgml/nullvalues.sgml.
I am confused by this word.

<sect3 id="nullvalues-usage-tables">
<title>Null Values in Tables</title>
<para>
Whether via the copy method above, or by inserting literal null values,
most usage concerns for null values results from their presence in a table
column that lacks a <link
linkend="nullvalues-table-constraints">not-null constraint</link>.
</para>
We can simply say that, in a table,
if a specific column doesn't have a not-null constraint, null value
can exist in that column.
or maybe this part is unnecessary, we can remove it.

<para>
As noted in <xref linkend="json-type-mapping-table"/>, the JSON
specification's
null value is assigned its own type unlike in SQL. This introduces
an inconsistency
since the JSON null type's value is itself non-null. It is also
comparable to any
other JSON type, returning false for equality, and itself,
returning true for equality.
But an SQL value of json or jsonb type having a JSON null value is
considered non-null in SQL.

this part """But an SQL value of json or jsonb type having a JSON null
value is considered non-null in SQL"""
is the same as
"since the JSON null type's value is itself non-null.".
so i think removing this sentence "But an SQL value of json or jsonb
type having a JSON null value is considered non-null in SQL."
there is no meaning being lost.
(i think this is minor issue)

<sect2 id="nullvalues-settings">
<title>Null-Valued Settings</title>
<para>
There are none. During initialization all settings are assigned a
non-null value.
</para>
"There are none" kind of comes from nowhere.
I think you mean "There are no null-valued settings"?

<sect2 id="nullvalues-partitionkeys">
<title>Null Values in Partition Keys</title>
<para>
Presently, PostgreSQL requires that all the columns of a partition
key be included

here "PostgreSQL" should be decorated as <productname>PostgreSQL</productname>.