OpenStreetMap
Took my first osm xml file download yesterday – rhone-alpes.osm from CloudMade, 52m lines in 3.95Gb (uncompressed) so hardly planet.osm. Even so the parsing program needs large file support “cc -D_FILE_OFFSET_BITS=64”
First steps taken to parse out the node lat&lon pairs into array of doubles. Highest node id in rhone-alpes is 1.543.458.302 = 1.54Gnodes. Assuming this is not outrageously different from the number of nodes in planet.osm, we could store the lat&lon pairs for the planet in ~25Gb (2x8 bytes x 1.5Gnodes). That’s definitely do-able.
17m nodes of rhone-alpes loaded in 62 seconds on bog-standard laptop, so ~1.5hrs for the planet?
Discussão
Comentário de giggls em 26 de março de 2012 às 10:19
For new software pbf format will always certainly be the better choice than osm format.
Comentário de Jochen Topf em 31 de março de 2012 às 12:18
You can store the coordinates as integers and you’ll only need half the space. See the storage/byid stuff in Osmium on how this can be done. The reason this works is that the precision of the coordinates is limited anyway, because internally the OSM server also stores the coordinates as integers.