[OSM-talk] Relations not always brilliant

[Lester Caine]

Steve Hill wrote:
> On Mon, 7 Apr 2008, Frederik Ramm wrote:
> 
>> If it's done consistently, one can still create relations automatically later 
>> if desired.
> 
> But this is kind of the point - if you are able to automatically create 
> the relations (and presumably automatically fix them if someone makes the 
> way tags inconsistent with the relation tags) with very little effort, is 
> there a good reason to create them in the first place rather than deriving 
> that data as and when you need it?

I harp back to *MY* original request. That there is a mechanism created for 
managing hierarchical data properly. Looking for ref=M11 is no use what so 
ever if there are M11's in several countries?

Until there is some UNIQUE way of tagging high level relationships 
consistently, then there seems little point trying to fix fine detail at the 
lower level. It brings back up the simple problem of producing a unique list 
of objects in the data. How DO we currently identify all roads in the UK, so 
that we don't end up with some of the simply silly links that the likes of 
Autoroute returns when asking for a location.

We need a consistent UNIQUE index method that will allow all 'ref=M11' 
elements in the UK to be identified as that one element. This may need the 
is_in to be correctly flagged, but what is actually missing is some HASH 
method whereby M11,UK is identified as #12345 while M11,NZ is #12346. This may 
well need some automated methods to manage it, but until there is some 
agreement on HOW the problem should be solved is there any point discussing 
how you combine disjointed bits of some road and flag the direction 
information needed to direct people through them? If I am searching for UK 
information I need some means of identifying it without having to do polygon 
transforms on 100s of thousands of elements when the boundary surrounding them 
is not even complete yet :(

Please can we at least start with a set of objects that define the countries 
of the world and consistently uses them to define those elements that are 
within each country?

-- 
Lester Caine - G8HFL
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