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- Subject: Data logging data base?
- From: "Bob Paddock" <BPADDOCK@...>
- Date: Thu, 19 Jul 2001 08:31:35 -0400
I'm doing my very first Lua program, so go easy on me please. :-)
Thought I'd ask some advice from the Gurus before I shoot my self in my
foot in my naivete.
I have a data logging system that gives me the time as the number of seconds since Jan/1/2000, then 17 one byte Analog to Digital converter values. These values get scaled differently, but I already have working Lua code that handles that ok (I call one of 17 functions from a table that is an array of functions, as the data comes in).
My question is what is the most effective way to build a data base, for fast access? It will be write once, read many.
When extracting the data I will be giving a start and end time, and a
Because the data is sampled every three seconds for several days, this data base could get large fast. However I'm more interested in speed than disk space. Tho I don't want have to take up all of the computer memory with the data file.
I was thinking of converting the time value to a string like:
YEAR:MONTH:DAY:SECONDS_FROM_MIDNIGHT as the key, then a channel number in array format, to get the values.
Is there a better way?
One of the other requirements is that I be able to delete the data, on a
day/date range bases. Just put in NIL's?
Also what would be the best way to save/restore this file?