How to set ft_max_word_len=X ?

Hello )
How can I set ft_max_word_len to 250?
I tried to put


into my.cnf but it doesn’t change it.

i also tried this:

mysql> set ft_max_word_len=1000; ERROR 1193 (HY000): Unknown system variable 'ft_max_word_len'

and this

mysql> set-variable = ft_max_word_len=1000; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-variable = ft_max_word_len=1000' at line 1

What do you mean it doesn’t change it? How do you know? You have to rebuild indexes after changing it, BTW.