操作步骤

1. 创建一个文本搜索配置ts_conf，复制预定义的文本搜索配置english。

   CREATE TEXT SEARCH CONFIGURATION ts_conf ( COPY = pg_catalog.english );
   CREATE TEXT SEARCH CONFIGURATION

2. 创建Synonym词典。
   假设同义词词典定义文件pg_dict.syn内容如下：

   postgres    pg 
   pgsql       pg 
   postgresql  pg

   执行如下语句创建Synonym词典：

   CREATE TEXT SEARCH DICTIONARY pg_dict (
        TEMPLATE = synonym,
        SYNONYMS = pg_dict,
        FILEPATH = 'file:///home/dicts'
    );

3. 创建一个Ispell词典english_ispell（词典定义文件来自开源词典）。

   CREATE TEXT SEARCH DICTIONARY english_ispell (
       TEMPLATE = ispell,
       DictFile = english,
       AffFile = english,
       StopWords = english,
       FILEPATH = 'file:///home/dicts' 
   );

4. 设置文本搜索配置ts_conf，修改某些类型的token对应的词典列表。关于token类型的详细信息，请参见解析器。

   ALTER TEXT SEARCH CONFIGURATION ts_conf
       ALTER MAPPING FOR asciiword, asciihword, hword_asciipart,
                         word, hword, hword_part
       WITH pg_dict, english_ispell, english_stem;

5. 在文本搜索配置中，选择设置不索引或搜索某些token类型。

   ALTER TEXT SEARCH CONFIGURATION ts_conf
       DROP MAPPING FOR email, url, url_path, sfloat, float;

6. 使用文本检索调测函数ts_debug()对所创建的词典配置ts_conf进行测试。

   SELECT * FROM ts_debug('ts_conf', '
   PostgreSQL, the highly scalable, SQL compliant, open source object-relational
   database management system, is now undergoing beta testing of the next
   version of our software.
   ');

7. 可以设置当前session使用ts_conf作为默认的文本搜索配置。此设置仅在当前session有效。

   \dF+ ts_conf
         Text search configuration "public.ts_conf"
   Parser: "pg_catalog.default"
         Token      |            Dictionaries             
   -----------------+-------------------------------------
    asciihword      | pg_dict,english_ispell,english_stem
    asciiword       | pg_dict,english_ispell,english_stem
    file            | simple
    host            | simple
    hword           | pg_dict,english_ispell,english_stem
    hword_asciipart | pg_dict,english_ispell,english_stem
    hword_numpart   | simple
    hword_part      | pg_dict,english_ispell,english_stem
    int             | simple
    numhword        | simple
    numword         | simple
    uint            | simple
    version         | simple
    word            | pg_dict,english_ispell,english_stem
   SET default_text_search_config = 'public.ts_conf';
   SET
   SHOW default_text_search_config;
    default_text_search_config 
   ----------------------------
    public.ts_conf
   (1 row)