Also in many processes, there are things going on at various time scales. Tight feed back loops are good for higher frequency phenomena. Ignoring the slower p

Also in many processes, there are things going on at various time scales. Tight feed back loops are good for higher frequency phenomena. Ignoring the slower phenomena can make you like the kids who see the water retreating, build a sandbox, and then come back in the evening to see it all underwater. So many places have all the log data, terabytes, maybe petabytes, but just for three months. What happened last year? When can we expect traffic to break this scaling assumption and need a refactor, this year or next? Impossible to know, unless you make your own copies of summary data and stay around for a few years.