I search the internet regarding the correct variable in my.cnf file. Some said that key_buffer_size is depreciated, but some said that key_buffer_size is the correct variable in my.cnf.

So, what is really the correct variable here? Is it key_buffer or key_buffer_size?

I'm using ubuntu 12.04.

And also I have the two key_buffer variable in my.cnf file. This is what I got after installing mysql.

The first one is located under this:

[mysqld]
key_buffer              = 16M

The other one is located under this:

[isamchk]
key_buffer              = 16M