Re: Patch for collation using ICU

> Bruce Momjian wrote:
> >
> > There are two reasons for that optimization --- first, some
> > locale support is broken and Unicode encoding with a C locale
> > crashes (not an issue for ICU), and second, it is an
> > optimization for languages like Japanese that want to use
> > unicode, but don't need a locale because upper/lower means
> > nothing in those character sets.
>
> No, upper/lower means nothing in those languages, so why would you need
> to optimize upper/lower if they're not used??
> And if they are, it's obviously because the text contains characters
> from other languages (probably english) and as such they should behave
> correctly.

Yes, Japanese (and probably Chinese and Korean) languages include
ASCII character. More precisely ASCII is part of Japanese
encodings(LATIN1 is not, however). And we have no problem at all with
glibc/C locale. See below("unitest" is an UNICODE database).

unitest=# create table t1(t text);
CREATE TABLE
unitest=# \encoding EUC_JP
unitest=# insert into t1 values('abcあいう');
INSERT 1842628 1
unitest=# select upper(t) from t1;
upper
-----------
ABCあいう
(1 row)

So Japanese(including ASCII)/UNICODE behavior is perfectly correct at
this moment. So I strongly object removing that optimization.
--
Tatsuo Ishii