“Is a traffic jam going to happen in this highway? And is then convenient to reallocate travelers based upon the forecast?” “By looking at the click stream coming from a given IP, can we notice the shifts of interest of the person behind the computer?” “Which contents of the news Web portal are attracting more attention? Which navigation pattern would lead readers to other news related to those contents?” “Are trends in medical records indicative of any new disease spreading in given parts of the world?” “Where are all my friends meeting?”  “In the financial context, can we detect any intraday correlation clusters among stock exchange?”  Although the information is often available, there’s no software system capable of computing the answers - indeed, no system enables users even to issue such queries.