dict_voikko

PostgreSQL full text search dictionary extension utilizing the Finnish dictionary Voikko.

dict_voikko uses the base form of Finnish words as lexems. For compound words it uses the base form of the non-compound words from which the compound word is built. If dict_voikko doesn't recognise the it returns NULL, so dict_voikko should always be chained with another dictionary.

Dependencies

The dictionary needs libvoikki and its dependencies. A suomi-malaga dictionary with morphological analysis for Voikko is neede (e.g. dict-morpho from http://www.puimula.org/htp/testing/voikko-snapshot/) and at the moment it needs to be called mor-morpho.

Installation

Put dict_voikko in [POSTGRES]/contrib/ and compile.

Compilation and install on Debian linux

apt-get install voikko-fi
apt-get install libvoikko-dev
make USE_PGXS=1
make install
wget http://www.puimula.org/htp/testing/voikko-snapshot/dict-morpho.zip
unzip dict-morpho.zip
mv mor-morpho/ /usr/lib/voikko/2/

Note: libvoikko versions 4.0+ require different morpho-files, from http://www.puimula.org/htp/testing/voikko-snapshot-v5/. Those files should be put into /usr/lib/voikko/5/, instead of /usr/lib/voikko/2/

###In PostgreSQL

Run something like:

CREATE EXTENSION dict_voikko;

CREATE TEXT SEARCH DICTIONARY voikko_stopwords (
    TEMPLATE = voikko_template, StopWords = finnish
);

CREATE TEXT SEARCH CONFIGURATION voikko (COPY = public.finnish);

ALTER TEXT SEARCH CONFIGURATION voikko 
    ALTER MAPPING FOR asciiword, asciihword, hword_asciipart, word, hword, hword_part 
    WITH voikko_stopwords, finnish_stem;

Test with

select ts_lexize('voikko', 'kerrostalollekohan');

The result should be:

 ts_lexize   
-----------
 {kerros,talo}
(1 row)