On Wed, Feb 26, 2020 at 11:56 AM James K. Lowden <jklow...@schemamania.org> wrote: > > and I want to avoid storing repetitive data, so that the database > > should contain > > [...] > > only the earliest time with the unchanging value is stored. > > Be careful what you wish for. Usually "avoid storing" is a proxy for > some kind of intended use. Unless it's infeasible, it's usually better > to store everything, verbatim, as it arrives. Then you can present it > however you like, with nothing lost.
A lot of process measurement instrumentation returns some nominal values, for instance firmware version. Do we store it or not? Storing it every second is silly, but if we drop it, we wouldn't be able to for instance audit if the statistics changed in some subtle way because of a firmware bug. This 'store only changed values' is intended for situations like that. Another suitable candidate for that treatment might be a status, for instance 'on battery' value for a UPS monitoring system. I can't think of a scenario where storing it every time would be better. The only disadvantage I can think of would be incidental, like monitoring the monitoring system itself: a long period of 'no data' could be caused by a monitoring failure as well as by the value not changing; but if that is a concern, I think it would be better to store a single heartbeat rather than possibly multiple unchanging values. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
