That's not a bad idea, at least for historical data. But actually one of the most common thing in sensor network monitoring is last readings monitoring. With indexes what I can do is : SELECT * FROM measures_xx ORDER BY timestamp DESC LIMIT 1 => And I got the very last reading in a blink (one page reading only). It shall be complicated that way... it can only be done by a mass update on a table each time I receive a packet... Also it's very important to have last 24h readings aggregate by hour or minutes (to plot a graph). So I can't go that way.... I think I must keep the timestamp index where it is but I should probably get rid of the others.
Thank you again for your help people Regards Loic Petit
