Re: [HACKERS] locales and encodings Oh MY!

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> With how similar straight C and en_US.UTF8 are it was suggested to me,
>> by persons who are far more C knowledgeable then I in my office, that
>> this is something the PG community could "fix" . A "fix" being so that
>> "col LIKE 'foo%' " could use btree indexes in locales like en_US.UTF8
>> (and probably some others).

>> is the request unreasonable ? anyone got any idea of the price tag to
>> make that happen ?

> I thought it already did that.

No, and the odds of it ever happening are insignificant. The sort order
associated with en_US (and other "dictionary order" locales) is just too
randomly different from what you need to optimize a LIKE search.
(Whoever told you en_US sorts similarly to C is nuts.)

The solution if you want the database's prevailing sort order to be en_US
is to put an extra text_pattern_ops index on the column you want to do
LIKE searches on. We might eventually have the ability to spell that
"put a C-locale index on the column", but text_pattern_ops is the way to
do it today.

regards, tom lane