Re: Can pg_trgm handle non-alphanumeric characters? - Mailing list pgsql-hackers

Fujii Masao <masao.fujii@gmail.com> writes:
> On Fri, May 11, 2012 at 12:07 AM, MauMau <maumau307@gmail.com> wrote:
>> Thanks for your explanation. Although I haven't understood it well yet, I'll
>> consider what you taught. And I'll consider if the tentative measure of
>> removing KEEPONLYALNUM is correct for someone who wants to use pg_trgm
>> against Japanese text.

> In Japanese, it's common to do a text search with two characters keyword.
> But since pg_trgm is 3-gram, you basically would not be able to use index
> for such text search. So you might need something like pg_bigm or pg_unigm
> for Japanese text search.

I believe the trigrams are three *bytes* not three characters.  So a
couple of kanji should work just fine for this.
        regards, tom lane