VerticaTips-Getting a Word Count

Vertica REGEXP_COUNT 函数返回正则表达式与字符串匹配的次数。您可以使用它来创建自己的用户定义 SQL 函数，用于计算字符串中的单词数。

dbadmin=> CREATE OR REPLACE FUNCTION get_word_count(x varchar) RETURN INT  
dbadmin-> AS  
dbadmin-> BEGIN  
dbadmin-> RETURN regex_count(x, '[\w-]+');  
dbadmin-> END;  
CREATE FUNCTION  
  
dbadmin=> SELECT get_word_count('The Vertica Analytics Platform is purpose built from the very first line of code for Big Data analytics.');  
get_word_count  
----------------  
18  
(1 row)  
  
dbadmin=> SELECT get_word_count('Vertica allows you to analyze your data not only in place, but in the right place – without data movement – while supporting any major cloud deployment for fast and reliable read and write for multiple data formats!');  
get_word_count  
----------------  
36  
(1 row)  
  
dbadmin=> SELECT get_word_count('Vertica relies on a tested, reliable distributed architecture and columnar compression to deliver blazingly fast speed. A simplified license and the capability to deploy anywhere delivers on the promise of big data analytics like no other solution.');  
get_word_count  
----------------  
37  
(1 row)