[OSM-dev] API 0.5 is on the way

Brett Henderson brett at bretth.com
Tue Sep 11 23:41:50 BST 2007

Frederik Ramm wrote:
> Hi,
> (posting to talk & dev with reply-to set to dev, dunno if that works)
>    those of you who also follow the "dev" list have seen that Gabriel 
> Ebner has recently presented a working prototype of "OSM without 
> segments", and I have created "OSM with relationships".
> We have combined those two into a shiny new "OSM 0.5" which we hope to 
> deploy in early October, provided that we don't encounter major obstacles
> and provided of course we have the support of the community and those
> who manage our essential servers (and take the blame if something 
> breaks...).
> The changeover from 0.4 to 0.5 will do away with segments, and at once
> remove all complexity associated with them - "unordered ways", "unwayed
> segments", and so on. The planet file will shrink by 40%, and API 
> performance, especially on bounding box downloads, will be greatly 
> improved as we're removing one level of indirection. Relationships
> will be rather unimportant in the beginning but their existence allows
> a great deal more tagging flexibility (turn restrictions, superways, 
> all that stuff).
Excellent work on all of this.  I had resigned myself to the fact that 
segments would be around forever.  I won't miss them :-)

As for relationships, I think they're an exciting idea.  They certainly 
appear to have the possibility to solve many of our current modelling 
problems.  I'm sure standards will take a while to standardise around 
their usage resulting in some heated mailing list discussions, but that 
is a good thing :-)
> Nodes and their history remain unchanged, but the history information 
> linked to segments and ways will be removed in the process. This is 
> unavoidable since the new model is structurally different from the old 
> model, and many historic ways simply cannot be represented in the new 
> model. 
I have to ask the question.  Is there any point maintaining history for 
nodes when way history has been lost?  Would it be better to make a 
clean break, and leave a read-only 0.4 api exposing history data and 
start from scratch.

I must admit that my reasons for asking this are selfish.  I'd love 
history tables to accurately reflect current data ...


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