how to change the Short description max character ?

[haishui]

Dear Experts:

I Have a questions on the proudct short descripton max character, and now, when I input over 400 character
I can't save my product, and get the below alert event,

1 error
the field description_short (English (English)) is too long : 400 chars max (count now 3912)

so I want increase the max character limit. but I have looked the mysql table product_lang the long descripton and short descripton is configure same. so I think the limit maybe not on mysql table,please kindly give a advices for the issue slove,thanks so much.

Best Regards.
Herny