Re: BUG #17676: Text comparison appears to be wrong

On Thu, Nov 3, 2022 at 12:56 PM PG Bug reporting form <
noreply(at)postgresql(dot)org> wrote:

> The following bug has been logged on the website:
>
> Bug reference: 17676
> Logged by: Rob Johnson
> Email address: robj(at)hightouchinc(dot)com
> PostgreSQL version: 14.5
> Operating system: Ubuntu
> Description:
>
> No tables are needed. Just ran this, comparing strings with lower-case 'x'
> and period '.' characters. The first two columns are false as expected,
> the
> last column is true, which appears to be wrong.
>
> => select '.' > 'x' as first, '.x' > 'x.' as second, '.xx' > 'x..' as
> third;
>
> List of databases
> Name | Owner | Encoding | Collate | Ctype | Access
> privileges | Size | Tablespace | Description
>
> ---------+----------+----------+-------------+-------------+-------------------+-------+------------+-------------
> nigeldb | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
>
> | 48 MB | pg_default |
>
>
Not a bug.

This just seems to be how UTF-8 Collation works; punctuation produces
non-obvious sorting outcomes.

https://superuser.com/questions/227925/in-utf-8-collation-why-11-is-less-then-1

I confirmed that explicitly adding COLLATE "C" produces the expected
outcome for third.

David J.