SELECT some_pk,regexp_split_to_table(some_column,'\s') as word
FROM some_table

获得不同的单词很容易：

SELECT DISTINCT word
FROM ( 
  SELECT regexp_split_to_table(some_column,'\s') as word
  FROM some_table
) t

或得到每个单词的计数：

SELECT word,count(*)
FROM ( 
  SELECT regexp_split_to_table(some_column,'\s') as word
  FROM some_table
) t
GROUP BY word