[odc-discuss] ODbL: Does publishing Produced Work from Derivative Database trigger Derivative Database ShareAlike?

Wed Mar 4 21:42:26 UTC 2009

Hi,

(For non-OSM people: "the planet file" = a large XML file that contains 
all of OpenStreetMap; "map tiles" = small PNG images produced from the 
dataase)

Richard Fairhurst wrote:
> I think this is an issue with the formats that are admissible for a  
> diff, not with the Produced Work question.

Agreed that both are different things that can be solved individually.

> My submission (and that of a few others) to the co-ment page is that  
> osm2pgsql, or indeed any other open source program on a widely used  
> platform, should be acceptable as a diff - i.e. "the program that  
> makes the [algorithmic] change". This solves the problem that  
> distributing a 5Gb PostGIS dump on demand is prohibitively expensive.

I do not think this goes quite far enough. For example, think about 
someone reading the data into his RDMS and creating a clever index that 
allows him to serve map tiles much faster. A proper "diff" cannot 
possibly be provided. A diff of your kind would perhaps include the full 
PostGIS source code. And what if the person uses Oracle?

Someone else wrote somewhere else "is it true that ODbL allows 
processing the data only with Open Source software" to which you rightly 
replied "no". But in this scenario, using Oracle suddenly becomes a 
showstopper because a diff cannot be provided, and neither can the 
source code that produces the diff. (It could be argued that even, say, 
compressing the planet file with a "shareware" compression utility, for 
which source is not available and which is not free, would land the user 
  in the same quandary.)

I think we should request the diff only where factual information has 
been added. I.e. if there *is* a computer program - any program - that 
creates the derived database from the original database (only), then the 
database need not be shared. Only if new data comes into the equation, 
e.g. for OSM, someone adds surveying labour etc., then I want the 
share-alike to work.

I know this is hard to express in watertight legalese but it is worth an 
attempt. - Matt Amos is right in saying that the unmodified 0.9 version 
would not have this problem at all but the unmodified 0.9 version will 
never be accepted by the OSM community so this is moot.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"