[OSM-talk] 'Allowed data'

[Lester Caine]

Martin Koppenhoefer wrote:
> 2013/12/7 Lester Caine <lester at lsces.co.uk <mailto:lester at lsces.co.uk>>
>
>     Delete is simply not a valid concept unless the object never existed in the
>     first place?
>
>
>
> While I find this concept appealing at first glance, it would raise complexity
> much more if we not only had present but also past objects in the db. We had a
> mapper in Germany (Mirko) who has mapped underground installations and old road
> infrastructure in that area that afterwards has been restructured. The density
> of objects (namely a second system of ways that wasn't in any way correlated to
> the current "ground") made editing in this area much more difficult than without
> these objects.
>
> If we want to be the map for everybody we also have to take care that complexity
> remains on a level that you can contribute even if you are not a full-time
> mapper or have studied OSM 1+2 at college ;-)

Which is exactly why the 'start_date' and 'end_date' become important elements. 
Rather than simply wiping those historic layers they get an end date, and the 
editors simply ignore them unless one has enabled a date range. This then 
replaces simply deleting perfectly good data and instead hides it away properly. 
The original proposal was that this data would get moved off to OHM, but that 
simply does not work when the bulk of the surrounding data is still required 
from the OSM version. I can see the 'need' to plot things like war campaigns on 
a second database, but the sort of historic data we are talking about here on 
the whole is closely linked with the rest of the live data and creating a 'date' 
slider to display an area over time would require a complete copy of the main 
database anyway?

-- 
Lester Caine - G8HFL
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