> To: Glyn Astill <glynastill@yahoo.co.uk>
> Cc: Björn Lundin <b.f.lundin@gmail.com>; "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>
> Sent: Thursday, 9 April 2015, 13:23
> Subject: Re: [GENERAL] unexpected (to me) sorting order
>
> On Wed, Apr 8, 2015 at 3:33 AM, Glyn Astill <glynastill@yahoo.co.uk>
> wrote:
>
>>
>>> From: Björn Lundin <b.f.lundin@gmail.com>
>>> To: pgsql-general@postgresql.org
>>> Sent: Wednesday, 8 April 2015, 10:09
>>> Subject: [GENERAL] unexpected (to me) sorting order
>>>
>>> select * from T_SORT order by NAME ;
>>>
>>> rollback;
>>> id | name
>>> ----+--------------------
>>> 1 | FINISH_110_150_1
>>> 2 | FINISH_110_200_1
>>> 3 | FINISH_1.10_20.0_3
>>> 4 | FINISH_1.10_20.0_4
>>> 5 | FINISH_1.10_30.0_3
>>> 6 | FINISH_1.10_30.0_4
>>> 7 | FINISH_120_150_1
>>> 8 | FINISH_120_200_1
>>> (8 rows)
>>>
>>> why is FINISH_1.10_20.0_3 between
>>> FINISH_110_200_1 and
>>> FINISH_120_150_1
>>> ?
>>>
>>> That is why is '.' between 1 and 2 as in 110/120 ?
>>>
>>>
>>> pg_admin III reports the database is created like
>>> CREATE DATABASE bnl
>>> WITH OWNER = bnl
>>> ENCODING = 'UTF8'
>>> TABLESPACE = pg_default
>>> LC_COLLATE = 'en_US.UTF-8'
>>> LC_CTYPE = 'en_US.UTF-8'
>>> CONNECTION LIMIT = -1;
>>>
>>>
>>
>>
>>
>> The collation of your "bnl" database is utf8, so the
> "." punctuation character is seen as a "variable element"
> and given a lower weighting in the sort to the rest of the characters.
> That's just how the collate algorithm works in UTF8.
>
> utf8 is an encoding method, not a collation. The collation is en_US,
> encoded in utf8. You can use C collation with utf8 encoding just fine.
> So just replace UTF8 with en_US in your sentence and you've got it
> right.
>
Yes, thanks for the correction there, and we're talking about the wider unicode collate algorithm.