Permanent ID: Unterschied zwischen den Versionen

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Service: In order to be really useful, a service should be implemented, which returns most recent Permanent ID even if an object has been changed (thus having another Permanent ID).
 
Service: In order to be really useful, a service should be implemented, which returns most recent Permanent ID even if an object has been changed (thus having another Permanent ID).
  
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== Alternative Encodings ==
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NOTE: Encoding OSM id with type (Node, Way, Relation) as integer (64 bit): osm_id = <node id> × 10 (eg. 123 → 1230), osm_id =  (<way id> × 10) + 1 (eg. 123 → 1231), osm_id (<relation id> × 10) + 4 (eg. 123 → 1234). (Source: Mapbox, see [https://docs.mapbox.com/vector-tiles/reference/mapbox-streets-v8/#openstreetmap-ids]). Example: "Schloss Kyburg" is a relation with id 1169711, so it becomes 11697114.
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Same "triple" values as above (osm type/id, version and coordinates) but with different encodings:
 
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Use OSM ID number (big integer 64 bit) together with OSM type (Node, Way, Relation)  
 
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* either with preceeding N,W,R as string.
 
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* or as integer (32 bit) with following formula: osm_id = <node id> × 10 (eg. 123 → 1230), osm_id =  (<way id> × 10) + 1 (eg. 123 → 1231), osm_id (<relation id> × 10) + 4 (eg. 123 → 1234). (Source: Mapbox, see [https://docs.mapbox.com/vector-tiles/reference/mapbox-streets-v8/#openstreetmap-ids]).  
 
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Additionally use these values for validation, separated e.g. by a "#":
 
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* version (small integer 16 bit) 
 
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* Latitude and Longitude (as centroid from line and polygons) as signed integers (32 bit) with a scale factor of 1e7, so an integer Latitude of -412870685 equates to -41.2870685 (as the original OSM database schema in "Rails port"), in order to retain a stable reference.
 
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Example: "Schloss Kyburg" having relation id 1169711 with version 5 at coordinates 47.4584, 8.74343 (see also above) becomes following Instant ID:
 
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  osm_pid2 = 11697114#5#474584000#87434300 => 11697114 plus osm_version = 5, osm_lat = 474584000, osm_lon = 87434300
 

Version vom 2. Mai 2019, 00:53 Uhr

This is an unofficial proposal for a "permanent ID" (osm_pid) for OpenStreetMap (OSM).

See https://wiki.openstreetmap.org/wiki/Permanent_ID for a more official state of discussions.

The goal is to get an opaque fixed length ASCII string. And that are the design considerations:

  • The OSM id alone is not stable enough (as probably most agree); and it can represent many concepts (and that's by design in OSM).
  • The version no. of the object is needed which makes clear which tags are (or have been) referred to.
  • Coordinates are needed, because a change of the way and area geometries does not increment the version number.

So a stable Permanent ID could have the following form (which leads to a fixed length string of 35 chars in total): 

 [N|W|R]<osm_id>#<version>[+|-]<lon>[+|-]<lat>

where:

  • N,W,R stands for Node, Way, or Relation.
  • osm_id ann unsigned big integer ("digits").
  • version is an unsigned integer with a hash in front.
  • coordinates (lat/lon) are signed floats (always showing the +/- sign), with a maximum of 6 digits. In case of a line (linestring) or an area/relation (polygon) geometries the coordinates taken into account are the lat/lon minimum of the geometry.

Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711, version #5 at coordinates 47.4584, 8.74343 which becomes following Permanent ID: 

 osm_pid = R1169711#5+47.4584+8.74343

Service: In order to be really useful, a service should be implemented, which returns most recent Permanent ID even if an object has been changed (thus having another Permanent ID).

NOTE: Encoding OSM id with type (Node, Way, Relation) as integer (64 bit): osm_id = <node id> × 10 (eg. 123 → 1230), osm_id = (<way id> × 10) + 1 (eg. 123 → 1231), osm_id (<relation id> × 10) + 4 (eg. 123 → 1234). (Source: Mapbox, see [1]). Example: "Schloss Kyburg" is a relation with id 1169711, so it becomes 11697114.

Von «https://giswiki.hsr.ch/index.php?title=Permanent_ID&oldid=67004»