Re: How to switch off Snowball stemmer for tsearch2?

On Wed, 22 Aug 2007, Dmitry Koterov wrote:

> Hello.
>
> We use ispell dictionaries for tsearch2 (ru_ispell_cp1251)..
> Now Snowball stemmer is also configured.
>
> How to properly switch OFF Snowball stemmer for Russian without turning off
> ispell stemmer? (It is really needed, because "Ivanov" is not the same as
> "Ivan".)
> Is it enough and correct to simply delete the row from pg_ts_dict or not?
>
> Here is the dump of pg_ts_dict table:

don't use dump, plain select would be better. In your case, I'd
suggest to follow standard way - create synonym file like
ivanov ivanov
and use it before other dictionaries. Synonym dictionary will recognize
'Ivanov' and return 'ivanov'.

>
> dict_name dict_init dict_initoption dict_lexize dict_comment
> en_ispell spell_init(internal)
> DictFile=/usr/lib/ispell/english.med,AffFile=/usr/lib/ispell/english.aff,StopFile=/usr/share/pgsql/contrib/english.stop
> spell_lexize(internal,internal,integer)
> en_stem snb_en_init(internal) contrib/english.stop
> snb_lexize(internal,internal,integer) English Stemmer. Snowball.
> ispell_template spell_init(internal)
> spell_lexize(internal,internal,integer) ISpell interface. Must have .dict
> and .aff files
> ru_ispell_cp1251 spell_init(internal)
> DictFile=/usr/lib/ispell/russian.med,AffFile=/usr/lib/ispell/russian.aff,StopFile=/usr/share/pgsql/contrib/russian.stop.cp1251
> spell_lexize(internal,internal,integer)
> ru_stem_cp1251 snb_ru_init_cp1251(internal)
> contrib/russian.stop.cp1251 snb_lexize(internal,internal,integer)
> Russian Stemmer. Snowball. WINDOWS (cp1251) Encoding
> ru_stem_koi8 snb_ru_init_koi8(internal) contrib/russian.stop
> snb_lexize(internal,internal,integer) Russian Stemmer. Snowball. KOI8
> Encoding
> ru_stem_utf8 snb_ru_init_utf8(internal) contrib/russian.stop.utf8
> snb_lexize(internal,internal,integer) Russian Stemmer. Snowball. UTF8
> Encoding
> simple dex_init(internal) dex_lexize(internal,internal,integer)
> Simple example of dictionary.
> synonym syn_init(internal)
> syn_lexize(internal,internal,integer) Example of synonym dictionary
> thesaurus_template thesaurus_init(internal)
> thesaurus_lexize(internal,internal,integer,internal) Thesaurus template,
> must be pointed Dictionary and DictFile
>

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