PostGIS

PostGIS

Developer(s)	Refractions Research, Paul Ramsey, Dave Blasby, Kevin Neufeld, Mark Cave-Ayland, Regina Obe, Sandro Santilli, Olivier Courtin, Nicklas Avén, Bborie Park, Pierre Racine, Jeff Lounsbury, Chris Hodgson, Jorge Arévalo, Mateusz Loskot, Norman Vine, Carl Anderson, Ralph Mason, Klaus Foerster, Bruno Wolff III, Markus Schaber
Initial release	April 19, 2001
Stable release	2.2.2 / March 22, 2016
Operating system	Linux, Windows, Mac OS X, POSIX-compliant systems
Type	Geographic information system
License	GNU General Public License (version 2 or later)
Website	http://postgis.net/

PostGIS (/ˈpoʊstdʒɪs/ POST-jis) is an open source software program that adds support for geographic objects to the PostgreSQL object-relational database. PostGIS follows the Simple Features for SQL specification from the Open Geospatial Consortium (OGC).

History

Refractions Research released the first version of PostGIS in 2001 under the GNU General Public License. After 6 release candidates, a stable "1.0" version followed on April 19, 2005.

In 2006 the OGC registered PostGIS as "implement[ing] the specified standard" for "Simple Features for SQL".^[1]

Features

• Geometry types for Points, LineStrings, Polygons, MultiPoints, MultiLineStrings, MultipPolygons and GeometryCollections.
• Spatial predicates for determining the interactions of geometries using the 3x3 DE-9IM (provided by the GEOS software library).
• Spatial operators for determining geospatial measurements like area, distance, length and perimeter.
• Spatial operators for determining geospatial set operations, like union, difference, symmetric difference and buffers (provided by GEOS).
• R-tree-over-GiST (Generalized Search Tree) spatial indexes for high speed spatial querying.
• Index selectivity support, to provide high performance query plans for mixed spatial/non-spatial queries.
• For raster data, PostGIS WKT Raster (now integrated into PostGIS 2.0+ and renamed PostGIS Raster)

The PostGIS implementation is based on "light-weight" geometries and indexes optimized to reduce disk and memory footprint. Using light-weight geometries helps servers increase the amount of data migrated up from physical disk storage into RAM, improving query performance substantially.

PostGIS is registered as "implements the specified standard" for "Simple Features for SQL" by the OGC.^[2] PostGIS has not been certified as compliant by the OGC. For the OGC's definition of compliant, see What does "Compliant" mean?.

Users

There are a large number of software products that can use PostGIS as a database backend, including:

• ArcGIS (via GISquirrel, ST-Links SpatialKit, ZigGIS, ArcSDE and other third-party connectors)
• Cadcorp SIS
• CartoDB
• CitySurf Globe
• ERDAS APOLLO
• Everest GIS
• Feature Manipulation Engine
• GeoMedia (via third-party connectors)
• GeoServer
• Gisgraphy^[3]
• GRASS GIS (GPL)
• gvSIG (GPL)
• Interoperability Extension from Esri
• Ionic Red Spider
• Kosmo (GPL)
• Manifold System
• MapInfo Professional
• Mapnik (LGPL)
• MapDotNet Server
• MapServer (BSD)
• MapGuide (LGPL)
• MezoGIS
• Nominatim,^[4] which powers the OpenStreetMap website
• OpenJUMP (GPL)
• QGIS (GPL)
• Spatial Manager™
• Skylinesoft TerraExplorer™
• TerraLib (LGPL)
• TerraView (GPL)
• TileMill, ^[5]
• uDig (LGPL)
• Uber (company)

See also

• Well-known text and binary, descriptions of geospatial objects used within PostGIS

References

1. PostGIS History
2. OGC Implementing Product Details Open Geospatial Consortium
3. http://www.gisgraphy.com/
4. http://www.nominatim.org/
5. https://www.mapbox.com/tilemill/

External links

• PostGIS
• Planet PostGIS
• PostgreSQL
• pgRouting

Tutorials

• Intro to PostGIS
• PostGIS tutorial
• Getting started with PostGIS An Almost Idiot's Guide

Documentation

• PostGIS HTML Documentation.
• PostGIS 2.1.8 PDF Manual.
• PostGIS in Action, 1st edition in hard-copy April 2011, 2nd Edition came out May 2015 from Manning Publications.

Other

• Frank Warmerdam, PostGIS: A Standards Based Geographic Extension for PostgreSQL, presentation at PGCon 2008.