A few months ago, I was awakened to the insistent buzzing and chirping of my BlackBerry telling me I had a high-priority message. All the customers who used one of my databases were calling in complaining that our Web application was taking 20 to 30 seconds to load the pages they used the most. Performance had gradually worsened over the prior few weeks and was now at the point where just a few more people logging in would bring the system down. I had to find the source of the problem—and ...