Re: 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
givena 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.