By default it will have some setting. That will be too low. If you get mysql error please create that file and update the contents. If you have any problem still you need to optimise your database.
I am very interested in all the helpfull information about server tune-ups and see that one of the main things is tweaking the my.cnf file. I am unable to find one. When I run "locate my.cnf" from the root, allI get is this: