Re: Empty String Comparison Standard compliant?

On Fri, 30 Jan 2004, Christoph Haller wrote:

> Just a short question (PostgreSQL 7.3.4 on hppa-hp-hpux10.20, compiled by GCC 2.8.1)
>
> SELECT ('' > 'GDMF') ; SELECT ('GDMF' > '');
>  ?column?
> ----------
>  f
> (1 row)
>
>  ?column?
> ----------
>  t
> (1 row)
>
> Are these results standard compliant?

I think so in general.  If the two lengths are not equal, then
"effectively" the shorter string is replaced by an extended version.  If
it's NO PAD (varchar/text for us) the character used is a character that
sorts less than any string.  Otherwise (char) it's a space.  Then you use
the collating sequence to determine the value of >.  Most will put space
before any of GDMF, so the above seems reasonable.