Re: BPCHAR description in 8.3. Character Types is misleading and incomplete

On Thursday, October 16, 2025, Jeff Davis <pgsql(at)j-davis(dot)com> wrote:

> On Thu, 2025-10-16 at 08:36 -0400, David G. Johnston wrote:
> > A given value has a finite length and there is just no restriction on
> > what that length is. All trailing spaces in the input are considered
> > padding for purposes of comparison i.e., manually padding is added by
> > the user as opposed to the system.
>
> I see -- so it means that the padding came from somewhere else (not the
> type).
>

Yeah, your original conclusion this couldn’t be labeled blank-padded seems
to have drawn this confusion. If padding is indeed noun-like and not
verb-like then calling it blank-padded works ok. The clarifying text is
then just fine as-is: the comment about any included spaces are
semantically insignificant ties back to calling those spaces “padding” and
thus the type itself remains “blank-padded” in both the and N and non-N
cases. There isn’t a way to make “trimmed” a noun here but those spaces
are not actually removed/trimmed away.

In short, I would change trimmed to padded in the table.

I’d also add “padding” here just to actually use the word in its noun form.

…but trailing spaces are [stored as] semantically insignificant [padding].

(I thought also about trying to remove the phrase “semantically
[in]significant” altogether but at the moment would rather not touch the
following paragraph.)

If we really have to drive the point home I'd also add a footnote marker to
“blank-padded” and then say in the footnote text (right below the table):
A blank-padded value contains zero or more trailing spaces which are
ignored for comparison purposes. These spaces are also called
“semantically insignificant”.

David J.