Re: Case sensitive full text searching

On Wed, 3 Sep 2008, Fco. Mario Barcala Rodr?guez wrote:

> Hi all:
>
> Is there any way to create a case sensitive full text index? My target
> is to make case sensitive full text searches but I don't know how.
>
> I could create a configurario for full text searching:
>
> CREATE TEXT SEARCH CONFIGURATION public.myconfiguration (PARSER =
> pg_catalog.default);
>
> CREATE TEXT SEARCH DICTIONARY public.my_dict (
>    TEMPLATE = pg_catalog.simple,
>    STOPWORDS = my_stops
> );
>
> ALTER TEXT SEARCH CONFIGURATION myconfiguration
>    ALTER MAPPING FOR asciiword, asciihword, hword_asciipart,
>                      word, hword, hword_part
>    WITH my_dict;
>
> And then create the full text index:
>
> CREATE INDEX textindexsensible ON documento
> USING gin(to_tsvector('myconfiguration',texto));
>
> But default behaviour of Simple Dictionary returns the lower-cased form
> of the word if it isn't in stopwords list. Is there any way to change
> this behaviour?

If you don't need any dictionary, why do you use simple dictionary ?
Instead, you can write dummy dictionary, which just checks for stopwords.
Another option, is write simple wrapper around simple dictionary, which
returns array (lexem_from_simple_dic, original_lexem).  Then you can
have two different configurations - one for case sensitive search
(uses this wrapper dictionary for query) and another one - for more broader
search.

Looks like  we can take this into account in our future work on improving
flexibility of text search.

Oleg


>
> Thanks in advance,
>
>  Mario Barcala
>
> P.S. I am using PostgreSQL 8.3
>
>
>

     Regards,
         Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83