[OSM-dev] Planet File Change Request

Frederik Ramm frederik at remote.org
Tue Sep 1 22:59:37 BST 2009


Mark Granger wrote:
> a few hundred or thousand
> ways in each file referenced non-existant nodes

That's because they were created after the node section had already been 
written out.

> There are probably also 
> some nodes that have bad locations and some ways that reference the 
> wrong nodes

No, unless with "bad locations" you mean that you don't see a change 
that has been made after the nodes had already been written out.

> A better solution would be for the planet file creation process to wait 
> a day and automatically apply the next day's diff file to the database 
> before uploading it.

I understand that such "fixed diffs" are already avaialable from hypercube.

> The only downside I can see to this change is that 
> we will have to wait one more day for the release of the planet files.

Which is completely unacceptable to many.

> Considering that this will make the planet files 100% complete, I think 
> that this is a worthwhile tradeoff. I am assuming that the daily diff 
> file contains an instantaneous snapshot of the entire OSM database and 
> does not contain partial edits like the planetary files.

That is correct as these are generated from the history tables. It is 
possible to generate the planet file from the history tables as well, 
achieving a coherent snapshot. I think it hasn't been done yet because 
the old dev machine was overloaded anyway... with the new machine, this 
could perhaps be tried out.


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