Re: External Open Standards

On 22 May 2012 02:58, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
>> The problem is that people think that "ISO" means ISO 8601, whereas it
>> actually means ISO 9075.  I can see how that's an easy mistake to make,
>> though.
>
> ... especially since we keep referring to 8601 in our own docs.
> Does this mean we should do a global s/8601/9075/ in the docs?

Negative on the global replace. Some date/time functions legitimately
refer to 8601 (see the page on 'extract' for examples).

I had thought that to_char/to_timestamp might refer to 8601 for the
"ISO week date" feature, but there doesn't appear to be an explicit
mention on that page. Perhaps there should be?

The text in 8.5.2. Date/Time Output seems to be the culprit here. It
(thrice) names 8601 as the governing standard for the ISO output
datestyle, and it has some ancillary wording that would become awkward
if we just subbed in 9075 instead.

Currently the first few sentences read:

"The output format of the date/time types can be set to one of the
four styles ISO 8601, SQL (Ingres), traditional POSTGRES (Unix date
format), or German. The default is the ISO format. (The SQL standard
requires the use of the ISO 8601 format. The name of the "SQL" output
format is a historical accident.) "

I would suggest something like:

"The output format of the date/time types can be set to one of the
four styles ISO, SQL (Ingres), traditional POSTGRES (Unix date
format), or German. The default is the ISO format, which refers to ISO
9075, the SQL standard. (The name of the "SQL" output format is a
historical accident, it does not refer to the SQL standard.) "

The note I suggested earlier would probably need to change in light of
the above, too. Perhaps along these lines:

"Note: the output format specified by ISO 9075 is identical to that
specified in ISO 8601, except that the uppercase letter 'T' separating
the date part from the time part is replaced with a space for the sake
of readability."

Cheers,
BJ