Re: [Tzdist] [tzdist] #32 (service): managing historical data

[Lester Caine <[e-mail]>]

On 24/10/14 19:02, Paul Eggert wrote:
> Lester Caine wrote:
>> I would probably view this as optional, EXCEPT that if one takes the
>> situation of a simple device which is also creating a log of it's data
>> now correctly using UTC timestamps, it also needs to log any change in
>> version of data set used while creating that log.
> 
> That's not needed in the simple devices that I help maintain.  They log
> UTC.
> 
> If devices need to put local time into a log for some reason, then they
> can log the UTC offset.  That is simpler and more reliable than logging
> the tz version number would be.

You are right. I was mixing up a problem we had with legacy log files
which is avoided by logging the right data in the first place. However
it is still important to be able to identify the data set being used by
the device in case there is a question about accuracy of the logged data.

> The problem of managing historical data is one that primarily concerns
> operations and system maintenance.  It's not something that low-level
> devices should need to worry about.  So it should be OK to make any
> version-control features optional.

Software that needs to support archival data simply need to say if a
suitable source is not available, but again even if the source is unable
to provided an historic few of the data, the version number is still an
important audit device.

-- 
Lester Caine - G8HFL
-----------------------------
Contact - http://lsces.co.uk/wiki/?page=contact
L.S.Caine Electronic Services - http://lsces.co.uk
EnquirySolve - http://enquirysolve.com/
Model Engineers Digital Workshop - http://medw.co.uk
Rainbow Digital Media - http://rainbowdigitalmedia.co.uk