How to switch off Snowball stemmer for tsearch2?

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:

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