[OSM-dev] Chopped of ways. Change Default or remove ID

Jochen Topf jochen at remote.org
Thu Aug 14 10:29:55 BST 2008


On Thu, Aug 14, 2008 at 07:09:26PM +1000, Brett Henderson wrote:
> Wolschon Softwaredesign und Beratung wrote:
>> On Thu, 14 Aug 2008 10:31:04 +0200, Jochen Topf <jochen at remote.org> wrote:
>>   
>>>> I propose to not modify ways by default and to remove the way-id of
>>>> ways that are modified during extraction.
>>>> What should a tool care if the way references node-ids that it has
>>>> no nodes for because they are outside the bounding-box? It has to ignore
>>>> them.
>>>>
>>>> The removal of the ID is because this is no longer the way with
>>>> that ID but a new and artificially created way that contains a part
>>>> of the original one.
>>>>       
>> ...
>>   
>>> There is another option, I want to bring into the discussion: In the
>>> case of the Osmosis extract we could keep the node list, but not include
>>> the nodes itself. This would keep the way object intact for the price of
>>> breaking referential integrity. This is the solution employed for
>>> relations, which are not resolved recursively (or only to a certain
>>> degree). This way we don't have to make objects incomplete. Still
>>> wouldn't solve the imcomplete tag thing.
>>>     
>>
>> That is exactly what I proposed with "not modify ways" and is also
>> what I do in Traveling Salesman when working with much less then a
>> whole planet for routing.
>>
>> Marcus
>>   
> Yeah, it's also what I meant when I said I was planning to change  
> osmosis to not mangle ways by default.  I didn't mean switch to the  
> --bounding-box completeWays=true functionality because that is not  
> scalable to large data sets.

Problem is: When used that way all the software that assumes that there
is a node for every node reference (like Osmarender) will fall on their
nose if they get this data...

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298





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