[OSM-dev] Ways with 40k nodes, was: osmosis pgsql schema

Shaun McDonald shaun at shaunmcdonald.me.uk
Fri Oct 31 12:12:16 GMT 2008


On 31 Oct 2008, at 11:51, Stefan de Konink wrote:

> Dave Stubbs wrote:
>> On Fri, Oct 31, 2008 at 11:02 AM, Stefan de Konink  
>> <stefan at konink.de> wrote:
>>> On Fri, 31 Oct 2008, Frederik Ramm wrote:
>>>
>>>> Any comments?
>>> You are now basically working around the actual problem. Allowing  
>>> partial
>>> ways in the editors for the current bbox. I think hacking and  
>>> breaking
>>> ways is bad, duplicate information, missing tags upon edit etc. I  
>>> think
>>> storing ways with their tags per 'new segment' is bad too; hence the
>>> reason I proposed to use an ordered relation to represent ways.
>>
>>
>> With 40k nodes in a way it takes the API about 30 seconds just to
>> generate and serve the XML for the way, /without/ the nodes.
>> The .osm file with no node data goes upto about 100kb. (With node  
>> data
>> that's 5-6MB)
>> To make a modification to the way, ie: add a tag, you have to  
>> reupload
>> that 100kb of XML, and sit back, probably make a cup of coffee to  
>> pass
>> the time.
>
> Fix the API. (and the implementation if it takes you that long ;)

Actually this isn't just an implementation problem, it is also a  
social limit. If 12 people were to request large highly detailed areas  
(and they were on a slow network connection), then you suddenly have  
everyone else locked out from doing bulkapi requests, until they have  
cleared.

There are other better ways to get large amounts of data, such as  
mirror API servers or the planet file. With the exposure of the node/ 
way/relation version numbers in API 0.6 this will make it much easier  
to deal with mirrored api servers.

>
Shaun
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