PostGIS Resources
- PostGIS Community Site
- PostGIS Issue Tracker
- PostGIS SVN Repository
- Spatial Database Tips & Tricks
- PostGIS Chat Room
OpenGeo Services
OpenGeo offers PostGIS training, including introductory and advanced sessions, as well as PostGIS core development to add new features to the project.
Our PostGIS Team
Paul has worked on geospatial software for over 13 years, as a programmer and consultant. He co-founded the PostGIS spatial database project in 2001, and is an active developer and project steering committee member.
Samuel has worn multiple hats during his 12-year affair with spatial technologies: user, print cartographer, web-mapper, integrator, scripter/programmer, trainer, analyst, manager.
About PostGIS
PostGIS “spatially enables” the PostgreSQL open source relational database. The database can then be used to store and query spatial data (points, lines and polygons).
- High performance, robust spatial database built on PostgreSQL
- Simple Features for SQL (SFSQL) compliance
- Proven reliability and transactional integrity (ACID compliance)
- Provides spatial representations of geometry types (points, lines, polygons)
- Support for common and advanced spatial operations such as geometry creation and conversion, reprojection, buffer, convex hull, generalization, union, and more
- Geodetic support for measurements across the globe/dateline
- Command-line and graphical tools for flexible management
PostGIS is widely supported as a spatial database back-end to client and server software, including:
- Open Source Server: GeoServer, Mapserver, Mapnik, DeeGree, SharpMap
- Open Source Desktop: GRASS, QGIS, uDig, gvSIG
- Proprietary Server: ArcServer, Ionic Enterprise, MapDotNet Server
- Proprietary Desktop: ArcGIS, Manifold, Safe FME, CadCorp SIS, MapInfo Professional
PostGIS @ OpenGeo
Recent Contributions
OpenGeo funds ongoing development of PostGIS as part of our larger mission to make public geodata more accessible and usable to civil society. Recent contributions include:
- Addition of a "geography" type, allowing native indexing and functions on spherical (latitude/longitude) coordinates.
- Performance improvements to the ST_Union() aggregate and all other geometry aggregates.
- Addition of a GUI for Shape file loading.
- Upgrading the underlying geometry libraries.
- Coordination of the release of PostGIS 1.5.
- Coordination and maintenance work around the release of GEOS 3.2.2.
- Organization of a second code sprint for PostGIS.
Core Development Roadmap
Support for ST_Union(), ST_Difference(), and true/false predicate tests calculated natively on the sphere for the GEOGRAPHY type introduced in PostGIS 1.5.
Indexed Nearest Neighbor Searches
Currently nearest-neighbor searching is carried out with ad hoc tricks that expand a search radius until a candidate set is generated, then finding the closest value in the candidate set. A directly indexed approach would be optimally fast.
The PostGIS spatial index currently splits pages based on longest edge. This results in trees that have sub-optimal spatial clustering in the branches, which in turn makes for sub-optimal clustering. A packed R-Tree would provide the highest performance clustering.
