On Wednesday 20 April 2016, Jochen Topf wrote: > > Adding node locations to ways is a pain (and needs more than 32 GB > RAM these days for a full planet if you want to get it done in > reasonable time). So I experimented with adding the node locations to > the ways once and storing it in the OSM files. Works for XML, PBF, > and OPL. See my blog post at > https://blog.jochentopf.com/2016-04-20-node-locations-on-ways.html > for the full story.
From perspective of database design this of course introduces redundancy in the data which in turn bears the risk of introducing inconsistencies. For storing data temporarily during processing this is not generally a big deal because the processes writing and reading this data are well defined but as a general data exchange and storage format this would be highly problematic - depending on how a program reads the file it will potentially get different results if there are inner inconsistencies in the file. On a more general note: for the purpose of storing the OSM planet data in a form that is efficient to use and update wouldn't it make sense to store the node locations in a flat file separately from the rest instead of storing everything in a dynamically structured format like XML or PBF that can essentially only be read sequentially? Another thing: you say you throw away untagged nodes that are not member of any way - don't forget nodes can also be relation members. I don't know any practical case where an untagged node is a relation member but in principle this is possible and could make sense. -- Christoph Hormann http://www.imagico.de/ _______________________________________________ dev mailing list [email protected] https://lists.openstreetmap.org/listinfo/dev
