Can I get MySQL to perform queries without any kind of caching?

[eluser]warpspasm[/eluser]
I have a JSON controller that makes a number of MySQL queries. One of the queries seems to have gotten slower but I don't know which one it is.

The problem is that sometimes the query is slow and then other times it is faster (especially if I run the same request immediately afterwards.)

This leads me to believe that MySQL is doing some kind of caching?

So, my question is: How can I get CodeIgniter / MySQL to run queries without any kind of caching so that I can start tracing which query is causing the problems?

Thanks for any ideas on how to get started on this!

Chris