Working on some performance tuning for MySQL today. Here are by far the best resources I have found:
Best General Tuning Guide:
Expanded point from that Guide:
I ran into an issue when I adjusted a log file size (MySQL wouldn’t start), this was the fix:
In my case MySQL was running on a dedicated VPS with 2 Gb of Ram so I had quite a bit of room to work. If you are on shared hosting or even a VPS sharing space with Apache your numbers are going to look different. This was, of course, an effort to fix performance on a Drupal site that was running really really rough even though it has low traffic. The tuning helped a lot but I still have a ways to go.
Anyhow, thought I would pass the helpful links along as anyone searching for MySQL Performance tuning should be finding this stuff first imho.