Re: Order By weirdness?

This will relate to collation order, which is something that you can
specify.  Please see:
https://stackoverflow.com/questions/17225652/how-can-i-sort-the-postgres-column-with-certain-special-characters

On Sat, Jan 7, 2023 at 3:35 PM Carl Sopchak <carl@sopchak.me> wrote:

> I'm seeing something (very) unexpected with ORDER BY.  If I run this query:
>
> select txt
> from ( values('x12345'), ('xz1234'), ('x23456'), ('xz2345'), ('x34567'),
> ('xz3456') ) a(txt)
> order by txt;
>
> I get expected results with x<#> being sorted before xz.  However, if I
> replace the z's with ~, giving
>
> select txt
> from ( values('x12345'), ('x~1234'), ('x23456'), ('x~2345'), ('x34567'),
> ('x~3456') ) a(txt)
> order by txt;
>
> I get this???
>
>   txt
> --------
>  x~1234
>  x12345
>  x~2345
>  x23456
>  x~3456
>  x34567
>
> Which appears to mean that ~ is treated differently than z (basically ~ is
> ignored).  Same if I use other special characters, such as @.
>
> Up until stumbling into this, I have never seen such behavior from a
> database.  (Windows OS, yes, but I won't go there...)  Character-based text
> always sorted in an alphabetic order (which puts special characters in
> different places in the ordering depending on encoding, but it's
> consistent).
>
> Two questions (which may be the same way of asking the same question):
>
> - How is this correct?  I can see where this could be useful in limited
> scenarios, but IMHO it makes no sense as a default sort order.
>
> - What do I need to do to get a strictly character-based sort in ORDER BY?
>
> I am using postgres version 14.3 on Fedora 37.
>
> Thanks for the help.
>
> Carl
>
>
>