Re: String comparison problem.

On Thu, May 29, 2008 at 9:45 PM, Theerasak Maneeneim
<theerasak(at)thns(dot)co(dot)th> wrote:
> Dear All,
>
> I have some problem with string comparison. I use postgresql
> 8.3.1,UTF8 encoding, on CentOS 5.5. Why dose the result of SQL statement :
> "select '1.1' < '101';" is false but "select '1.1'::bytea < '101'::bytea;"
> is ture?

The UTF encoding isn't what's important here, it's your locale, which
is likely something like en_US (but different, whatever you'd have in
your country). This locale will be collated (i.e. sorted etc.) by a
set of rules for the language where you live.

For instance, with a list like:

a dc
abc
a bc
adc

and an order by on it in locale en_US I get this ordering:

abc
a bc
adc
a dc

Why? Because according to the rules of english, spaces don't count.

If you want byte code ordering, then you need to use Locale=C when you
run initdb. Locale can only be changed at initdb time.