BUG #6495: mis-sorting on string field consisting of space-padded numbers

Hello

2012/2/28 <lou@paprikash.com>:

The following bug has been logged on the website:

Bug reference:      6495
Logged by:          Lou Duchez
Email address:      lou@paprikash.com
PostgreSQL version: 9.1.2
Operating system:   Fedora 16, CentOS 5
Description:

Download the following file and feed it into psql:

http://www.paprikash.com/lou/missorttest.sql

Then run the command:

select * from missorttest order by hiercode;

Each "hiercode" entry contains concatenations of numbers, where each number
is left-padded to take exactly four characters.  PostgreSQL is sorting as if
the padding were on the right.  As a result, "   2  10" is coming before "
2   2", even though a literal sorting of the string should put "   2   2"
first (because chr 32 comes before chr 49).

More info: this error does not occur on the Windows build of PostgreSQL.
Also, I compile my own versions of PostgreSQL on Fedora and CentOS, taking
all the defaults.

This should not be bug - this behave depends on system libraries and
locales setting.

Please, check value of lc_collate variable

postgres=> show lc_collate;
lc_collate
-------------
en_US.UTF-8
(1 row)

different collations should have different order.

Regards

Pavel Stehule