Is there a key-time-value database?
StrawberryFrog: Yes, products like this do exist.See http://en.wikipedia.org/wiki/Time_series_databaseThe oil industry uses them to record data points coming from hundreds of instruments on equipment on their oil rigs (pump pressure, engine temperature, pipe rate of flow, motor RPM, etc). The oil companies that operate them are rich, and there's big money at stake to optimise the flow of oil; not to mention lives at stake - Piper Alpha accident in 1988 cost 167 lives and £1.7 billion.The one that I saw used was OsiSoft Pi System http://www.osisoft.com/Products/PI%20System/