Permanent ID: Unterschied zwischen den Versionen

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This is an '''unofficial proposal for a "permanent ID" for OpenStreetMap ([[OSM]])'''.
#REDIRECT [[Permanent_ID_for_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 is left-padded with zeros to get 10 chars ("digits").
* version is 4 digits left padded with zeros.
* coordinates have 5 fixed decimal places (lat is 2 and lon is 3 digits wide, both are signed and left-padded with zeros).
 
Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711, version #5 at coordinates 47.4584, 8.74343 which becomes following Permanent ID:
 
  R0001169711#0005+47.45840+008.74343
 
Service: In order to be really useful, a service should be implemented, which returns most recent Permanent ID even if a an object has been changed (thus having another Permanent ID).
 
== Instant ID ==
 
For all those services which can't wait until a Permanent ID solution has been adopted by the OpenStreetMap software stack and community, following '''Instant ID''' (a biginteger triple) is being proposed:
 
* Use OSM ID number (biginteger) together with OSM type (Node, Way, Relation)
** either with preceeding N,W,R as string.
** or as biginteger 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]).
 
Additionally (optionally)
* use and store version (small integer 16 bit) 
* use and store Latitude and Longitude (as centroid from line and polygons) as 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.
 
Example: "Schloss Kyburg" having relation id 1169711 with version 5 at coordinates 47.4584, 8.74343 (see also above) becomes following Instant ID:
 
  11697114
  plus 5,474584000,87434300

Aktuelle Version vom 19. Juni 2019, 20:04 Uhr

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