What Is the Histogram of Response Times?

When you get to net working level, you really have to be careful about collecting a lot of really good statistics so that you know there is em because often problems go detected for a long undetected for a long time. And se would want to look at what do the longest one % of queries take, or 99%. What is the histogram of response times? You say, if you ever hear the term p 50 and p 99, it's what patrick's referring to. So i know that occasionally something will happen and i can't complete within a hundred millow seconds,. But i never want a request to take two too long.