User:Davetoo/GIS/postGIS

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Notes on using OSM data in GIS applications, using a postGIS back end.


OSM "simple" schema

Problems with "Relations"

Layers

GIS users will typically need only a subset of the map data features at any one time,

Attributes

Linestrings/MultiLineStrings

Can/should OSM 'relations' be used to represent multilinestrings?


Polygons/Multipolygons

  1. Find polygons identified from 'relations' table set
  2. If constructed from multiple ways, i.e. not truly a closed line, then
    1. We probably need to copy them to a new layer and then join them.