[ Thanks to Lee Schlesinger for this link. ]
Once WordPress has been up and running for some time
you can tweak your settings by running MySQLTuner, a Perl script
that analyzes your MySQL performance and, based on the statistics
it gathers, gives recommendations about which variables you should
adjust to increase performance. With MySQLTuner, you can tune your
my.cnf file to tease out the last bit of performance from your
MySQL server and make it work more efficiently.