Features Of PostGIS

PostGIS is not your standard spatial extension to a relational database… or is it?

PostGIS supports many standards:

• The Open GIS Consortium (OGC) standards for "Simple Features" (2D Geometries)
  • ​Simple Features at OGC
    • ​What does OGC mean by Openness and Open Standards?
  • ​Graphic of OGC Spatial Data Types implemented in JTS/GEOS code at JUMP site
  • ​Simple Features on Wikipedia

• The Open GIS Consortium (OGC) markup language for "Simple Features" known as Well Known Text (WKT) and Well Known Binary (WKB) representations of data.
  • ​WKT and WKB in PostGIS manual
  • ​WKT on Wikipedia
  • ​Download the PDF's on Simple Features at OGC

• OGC SQL functions: standards for managing spatial tables using SQL language
  • ​SQL for Simple Features at OGC
  • ​Discussion of Compliance in PostGIS manual
  • ​Direct Link to Functions in PostGIS manual

PostGIS extends support for geometry types:

• EWKB, EWKT and Canonical Forms
  • PostGIS adds support for embedding the SRID (projection information) and for 3 and 4D geometries with Z and M values, respectively.
    • ​EWKT and EWKT in PostGIS manual
    • ​EWKT on Wikipedia
• Other Types
  • Progress on Raster Support
  • ​Proposed X3D types: TIN and COLLADA for Web Output

PostGIS enables powerful spatial analysis and editing of geometries

• ​Spatial functions and operators in PostGIS manual
• ​Graphic of Spatial Analysis methods implemented in JTS/GEOS code at JUMP site
• ​Boston GIS PostGIS Functions Cheatsheet
• Additional User-contributed Functions

PostGIS can be extended by scripting with an array of languages

• Client-side extensions exist to access spatial data in PostgreSQL for the following programming languages:
  • Python | Scripting Examples
    • ​Psycopg: a PostgreSQL database adapter for Python
    • ​GeoTypes: an extension to Psycopg
  • Java | Scripting Examples
    • Included in PostGIS, supports own class model as well as JTS, and read-only support for Java2D
  • PHP | Scripting Examples
    • ​PHP example of writing to KML (in MySQL)
  • Ruby
    • ​GeoRuby's Spatial Adapter for Active Record
  • (I heard rumors of a perl interface, please edit)