[Legal-general] Who would start using an OSM PD repository?
mapping at sheerman-chase.org.uk
Wed Jul 21 09:37:10 BST 2010
I was thinking about how to maintain the central data for a PD dataset.
I think there is interest in PD within OSM but it has clearly not
translated into a PD branch (or fork). I am still struggling to
understand that failure, to avoid making the same mistakes.
On 20/07/10 17:40, Sunburned Surveyor wrote:
> I'm curious about how much and how serious the interest is in a public
> domain repository for data that would be pushed upstream to the
> regular OSM database.
If I understand you, you plan to download an OSM from from a file
repository (such as git or svn), edit it locally, and load back to the
Advantages of a repository:
Relatively simple to administrator and host
Large overall size is easily supported
Relatively simple to upload into the main SA dataset
No usernames, OSM usernames only get added to the data after uploading
and downloading from the main server AFAIK
No history of changes
Edges of tiles are difficult to handle
For densely mapped areas, an extreme number of separate files are needed
(local data editors cannot load entire cities)
Not easy to use, the main server is difficult enough. Finding the
correct file would be confusing, every country having a different
If multiple users make changes to the same area (accidentally), merging
the data might be difficult
Another approach is to use the existing software stack - known as "the
rails port" and written in ruby (on rails). I have this working on my
ubuntu desktop and it was relatively(?) easy to install. But I don't
know the ruby language (yet).
Accessing the data is relatively simple
Full edit history, user messaging system and sign up page
Potlatch should work, along with all other OSM tools
Difficult to administer, linux knowledge is uncommon, ruby knowledge is
rare. Who would do backups? Planet dumps? Bug fixes?
The rails port would need to be adapted for PD use, to remove duplicated
stuff from the main OSM page
OSM/PD usernames would probably be separate from OSM usernames (unless
some complex jiggery pokery was added)
Hosting the rails port requires more specialist hosting (repositories
are common, the rails port is a rare breed).
Uploading data to the main SA dataset might be tricky - node IDs would
differ between the PD and SA datasets. This might be rejected as a conflict.
Or a third approach is to implement a new server stack. This would not
be a good idea, unless the other options are completely unworkable. The
API for the main dataset periodically changes and we would need to keep
in step to use OSM tools. It would also duplicate effort.
If anyone can think of other pros and cons, I would be interested.
Conclusions: we don't need to choose right away. We can do one, then
transition to another option. The rails port seems to me the way to go,
eventually. If you have hosting with the USGS, it would do as a
temporary solution. I am personally not very interested in a repository,
until I thought there were PD mappers active in my area. The rails port
would need some adaptation to make it usable. Hosting the database is
another issue, as repository or on the rails port. What is OSMF's view
on this? Also, given the relicensing may cause an CC-SA-BY fork. What
are they doing in this area? Can our efforts be combined?
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