Re: BUG #15805: Problem with lower function for greek sigma (Σ) letter

"Daniel Verite" <daniel@manitou-mail.org> writes:
>     PG Bug reporting form wrote:
>> lower('ΔΗΜΟΤΕΣ ΦΑΙΣΤΟΥ') =
>> "δημοτεσ φαιστου" instead of "δημοτες φαιστου"

> With PostgreSQL version 10 or newer, you could use an ICU
> locale. lower() would produce the expected result:

Oh, if using ICU already fixes this, I think we might as well just
say that you have to use ICU if you want the right behavior for such
cases.

> The libc library provides an API with character-by-character
> case conversions (tolower/toupper), which is too limited
> to deal with the above cases, and PostgreSQL basically
> just uses this API.

Right.

            regards, tom lane