GBase 8c 词典-同义词词典

星号（*）可用于词典文件中的同义词结尾，表示该同义词是一个前缀。在to_tsvector（）中，该星号将被忽略，但在to_tsquery（）中会匹配该前缀并对应输出结果。
 

假设词典文件synonym_sample.syn内容如下：

postgres        pgsql

postgresql      pgsql

postgre pgsql

gogle   googl

indices index*

创建并使用词典：

gbase=# CREATE TEXT SEARCH DICTIONARY syn (template=synonym, synonyms='synonym_sample');

gbase=# SELECT ts_lexize('syn','indices');

 ts_lexize

-----------

 {index}

(1 row)

 

gbase=# CREATE TEXT SEARCH CONFIGURATION tst (copy=simple);

gbase=# ALTER TEXT SEARCH CONFIGURATION tst ALTER MAPPING FOR asciiword WITH syn;

gbase=# SELECT to_tsvector('tst','indices');

 to_tsvector

-------------

 'index':1

(1 row)

 

gbase=# SELECT to_tsquery('tst','indices');

 to_tsquery

------------

 'index':*

(1 row)

 

gbase=# SELECT 'indexes are very useful'::tsvector;

            tsvector             

---------------------------------

 'are' 'indexes' 'useful' 'very'

(1 row)

 

gbase=# SELECT 'indexes are very useful'::tsvector @@ to_tsquery('tst','indices');

 ?column?

----------

 t

(1 row)