[OSM-dev] Planet File Change Request

Mark Granger grangerfx at gmail.com
Wed Sep 2 18:54:53 BST 2009


As Frederik suggested, I downloaded the planet-090901.osm file from 
http://hypercube.telascience.org/planet/.

This is planet file that I presume was built by the hypercube site using the 
daily patches. When I parsed the file I found 120 ways that contained 
missing nodes. These may be the deleted nodes you describe. Regardless of 
why the nodes are missing, I am concerned that there seems to be no way to 
obtain a complete planet.osm file with all nodes and ways intact.

I am curious why this is not a bigger issue with users of the OSM dataset? 
If missing nodes are to be expected, shouldn't this be mentioned in the 
planet.osm wiki page? What is the best practice when we encounter a way with 
a missing node? Should we skip the node or delete the entire way. I have 
opted for the latter approach currently.

Also, I discovered that I have been downloading my planet files from the 
wrong site. I was using the planet.openstreetmap.org which the planet.osm 
wiki page (http://wiki.openstreetmap.org/wiki/Planet.osm) states should not 
be used in order not to overload the main server. I recomend changing the 
README file on the planet.openstreetmap.org site to tell users to use one of 
the mirrors listed on the wiki page.

-Mark Granger
----- Original Message ----- 
From: "Tom Hughes" <tom at compton.nu>
To: "Shaun McDonald" <shaun at shaunmcdonald.me.uk>
Cc: <dev at openstreetmap.org>
Sent: Tuesday, September 01, 2009 4:14 PM
Subject: Re: [OSM-dev] Planet File Change Request


> On 02/09/09 00:11, Shaun McDonald wrote:
>
>> On 1 Sep 2009, at 23:54, Tom Hughes wrote:
>>
>>> If you find recently created ways that reference deleted nodes then
>>> please let us know. If you find old ways that do it then just upload a
>>> new version and that will fix the data.
>>
>> I'm not convinced it works in all cases, as there is an assumption that
>> if a node is already in a way, or a member is already a member of a
>> relation then it is valid. This assumption was added to the code to make
>> it significantly faster to update larger ways and relations.
>
> Yes, you have to actually remove the deleted nodes from the way when
> reuploading because, as you say, existing deleted nodes are allowed to
> persist in the way even if the way is change. New deleted nodes can't be
> added however.
>
> Tom
>
> -- 
> Tom Hughes (tom at compton.nu)
> http://www.compton.nu/
>
> _______________________________________________
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> dev at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/dev 





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