Re: dangers of setlocale() in backend (was: problem with float8 input format)

> But your patch sounds incredibly useful :-) Has it been integrated in
> the mainline code yet? How does one use this functionality?

It never will integrated into the PG standard main tree, because it is
stupid patch for common usege :-( (and I feel ashamed of this :-)

> Also what is the main difference with using the standard gettext call?
>
> setlocale(LC_ALL, "en_US");

This ('LC_ALL') call load support for all locales categories (numbers,
text, currency...etc.). Inside postgreSQL it's dangerous, because it
change for example float numbers deciamal point..etc.

In the PostgreSQL are used (only):

setlocale(LC_CTYPE, "");
setlocale(LC_COLLATE, "");
setlocale(LC_MONETARY, "");

For more information see the file ustils/adt/pg_locale.c in PG sources, that
allows you to change and load *all* locales catg. and set it back to previous
state. It is used for to_char() that needs load LC_NUMERIC informations.

But again: after your functions you must always set correct locales.

And in 7.1 it will more important, because CurrentLocaleConv struct in
pg_locale.c that use to_char() is load only once --- it's performance
option. And not is a way how this struct change if it's already filled,
because we not expect on-the-fly locales....

Karel