## F.17. Hunspell Dictionaries Modules

These modules provide Hunspell dictionaries for various languages. Upon installation of the module into database using `CREATE EXTENSION` command, text search dictionary and configuration objects in the public schema appear.

Table F.10. Modules

Language | Extension name | Dictionary name | Configuration name
--- | --- | --- | ---
American English | `hunspell_en_us` | `english_hunspell` | `english_hunspell`
Dutch | `hunspell_nl_nl` | `dutch_hunspell` | `dutch_hunspell`
French | `hunspell_fr` | `french_hunspell` | `french_hunspell`
Russian | `hunspell_ru_ru` | `russian_hunspell` | `russian_hunspell`

### F.17.1. Examples

Text search objects will be created after installation of a dictionary module. We can test created configuration:

    SELECT * FROM ts_debug('english_hunspell', 'abilities');
       alias   |   description   |   token   |          dictionaries           |    dictionary    |  lexemes
    -----------+-----------------+-----------+---------------------------------+------------------+-----------
     asciiword | Word, all ASCII | abilities | {english_hunspell,english_stem} | english_hunspell | {ability}
    (1 row)

Or you can create your own text search configuration. For example, with the created dictionaries and with the `Snowball` dictionary you can create mixed russian-english configuration:

    CREATE TEXT SEARCH CONFIGURATION russian_en (
      COPY = simple
    );

    ALTER TEXT SEARCH CONFIGURATION russian_en
      ALTER MAPPING FOR asciiword, asciihword, hword_asciipart
      WITH english_hunspell, english_stem;

    ALTER TEXT SEARCH CONFIGURATION russian_en
      ALTER MAPPING FOR word, hword, hword_part
      WITH russian_hunspell, russian_stem;

You can create mixed dictionaries only for languages with different alphabets. If languages have similar alphabets then Postgres Pro can not decide which dictionary should be used.

A text search configuration which is created with a dictionary module is ready to use. For example, in this text you can search some words:

    SELECT to_tsvector('english_hunspell', 'The blue whale is the largest animal');
                   to_tsvector
    -----------------------------------------
     'animal':7 'blue':2 'large':6 'whale':3
    (1 row)

Search query might looks like this:

    SELECT to_tsvector('english_hunspell', 'The blue whale is the largest animal')
      @@ to_tsquery('english_hunspell', 'large & whale');
     ?column?
    ----------
     t
    (1 row)

With this configurations you can search a text using GIN or GIST indexes. For example, there is a table with GIN index:

    CREATE TABLE table1 (t varchar);
    INSERT INTO table1 VALUES ('The blue whale is the largest animal');
    CREATE INDEX t_idx ON table1 USING GIN (to_tsvector('english_hunspell', "t"));

For this table you can execute the following query:

    SELECT * FROM table1 where to_tsvector('english_hunspell', t)
      @@ to_tsquery('english_hunspell', 'blue & animal');
                      t
    --------------------------------------
     The blue whale is the largest animal
    (1 row)