OpenStreetMap 로고 OpenStreetMap

First osm xml download and parse

ViewFromTheBoundary님이 English로 2012년 3월 26일에 게시함.

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?

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토론

2012년 3월 26일 10:19giggls님의 의견

For new software pbf format will always certainly be the better choice than osm format.

2012년 3월 31일 12:18Jochen Topf님의 의견

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.

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