pg-search-thai

NOTE This repo has been updated to keep up with libthai 0.1.28-4 (Deb). Therefore, it's working with the new versions of Postgresql including 13 (the one I'm using with).

pg-search-thai is full text search PostgreSQL extension for Thai Language.

Its main purpose is:

To enable PostgreSQL Full Text Search in Thai language (Due to Thai Language does not use spaces to separate words)

Prerequisite

libthai, libiconv - this pg extension requires Thai word breaking functionality from the popular LibThai and libiconv. postgresql - pg_config in order to build this extension.

Installation

• Download the libthai (and its dependency: libdatrie ).

• Download the libiconv.

• Install libthai and libiconv on your local system.

• Install the extension from source, go to project root directory (cd pg-search-thai). Then, you can simply run:

  make all

• If you would like to install only the thai parser, just go into thai_parser directory. Then, compile and install it, like so:

  cd thai_parser; make; make install

Usage

• Start the psql console ( Or any postgresql client, pgAdmin for instance ) and create the extension you have just installed by typing following commands:

  CREATE EXTENSION thai_parser;

  CREATE TEXT SEARCH CONFIGURATION thaicfg (PARSER = thai_parser);

  ALTER TEXT SEARCH CONFIGURATION thaicfg ADD MAPPING FOR a WITH simple;

• Note: This extension is only tested with UTF-8 encoding. So, it is highly recommended to initial database with utf-8.

Example 1

Check how parser works.

SELECT * FROM ts_parse('thai_parser', 'ต้มยำกุ้งน้ำข้น ( Thai sour and spicy shrimp soup ) และไข่เจียวร้อนๆ');

Example 2

Try to build document from thaicfg configuration that uses the specified parser.

SELECT to_tsvector('thaicfg', 'ต้มยำกุ้งน้ำข้น ( Thai sour and spicy shrimp soup ) และไข่เจียวร้อนๆ');

Example 3

Querying

SELECT to_tsvector('thaicfg', 'the land of somtum (ส้มตำ)') @@ to_tsquery('thaicfg','ส้มตำ');
 ?column?
----------
 t
(1 row)

Example 4

Querying with | and & operator.

SELECT to_tsvector('thaicfg', 'ส้มตำไก่ย่าง ต้มยำกุ้ง in thailand') @@ to_tsquery('thaicfg','ข้าวเหนียว&ส้มตำ');
 ?column?
----------
 f
(1 row)

SELECT to_tsvector('thaicfg', 'ข้าวเหนียวส้มตำไก่ย่าง ต้มยำกุ้ง in thailand') @@ to_tsquery('thaicfg','ข้าวเหนียว&ส้มตำ');
 ?column?
----------
 t
(1 row)

Example 5

If you want to use hunspell as a dictionary for the full text search. Make sure you have already install thai hunspell dictionay files in pg_config --sharedir/tsearch_data directory.

CREATE TEXT SEARCH DICTIONARY thai_hunspell (
    TEMPLATE = ispell,
    DictFile = th_TH,
    AffFile = th_TH,
    StopWords = english
);

In psql console type \dFd to see if dictionary is installed. Then,

ALTER TEXT SEARCH CONFIGURATION thaicfg ADD MAPPING FOR a WITH simple, thai_hunspell;

And, test with,

SELECT ts_lexize('thai_hunspell', 'ทดสอบ');

Bugs Report and Contributing

GitHub issue tracker and pull requests are welcome.

pg-search-thai is released under the GNU General Public License (GPLv2). Refer to License FAQ for more information.