PostGIS

PostGIS is an open source, easy to install, and freely distributed software project, an extension for the PostgreSQL object-relational database server. It has been created from the ground up to implement support for geographic objects in PostgreSQL.

Allows PostgreSQL to be used as a backend spatial database for GIS

In other words, PostGIS "spatially enables" the PostgreSQL database engine, allowing it to be used as a backend spatial database for GIS (Geographic Information Systems), similar to Oracle's Spatial extension or ESRI's SDE.

There are now several open source tools which work with the PostGIS software. The uDig project is working on a full read and write desktop environment that can work with PostGIS directly.

Installing PostGIS on a PostgreSQL server

To install the PostGIS extension on your PostgreSQL database server, download the latest release from Softoware, save the archive on a location of your choice and unpack it in the ‘contrib’ directory of your PostgreSQL source tree.

Open a Terminal app, navigate to the extracted folder in the contrib directory using the ‘cd’ command (e.g. cd contrib/postgis-0.9.0), run the ‘make’ command to compile the extension, then run the ‘make install’ command as root or the ‘sudo make install’ command as a privileged user to install it.

Additionally, you must run the ‘createlang plpgsql yourtestdatabase’, the ‘psql -d yourtestdatabase -f postgis.sql’ and ‘psql -d yourtestdatabase -f spatial_ref_sys.sql’ commands, where “yourtestdatabase” should be the name of a test database.

Under the hood and supported OSes

While taking a quick look under the hood of the PostGIS software, we’ve noticed that its components where written in either SQL or Perl programming languages. The software can be installed on any Linux kernel-based operating system where a supported PostgreSQL server is available. Both 32 and 64-bit computer platforms are supported at this time.

What is new in this release:

• This is a minor release which fixes some bugs, contains speed improvements and additional features.

What is new in version 1.5.1:

• Bug Fixes
• #410, update embedded bbox when applying ST_SetPoint, ST_AddPoint ST_RemovePoint to a linestring
• (Paul Ramsey)
• #411, allow dumping tables with invalid geometries
• (Sandro Santilli, for Regione Toscana-SIGTA)
• #414, include geography_columns view when running upgrade scripts
• (Paul Ramsey)
• #419, allow support for multilinestring in ST_Line_Substring
• (Paul Ramsey, for Lidwala Consulting Engineers)
• #421, fix computed string length in ST_AsGML()
• (Olivier Courtin)
• #441, fix GML generation with heterogeneous collections
• (Olivier Courtin)
• #443, incorrect coordinate reversal in GML 3 generation
• (Olivier Courtin)
• #450, wrong area calculation for geography features that cross the date line
• (Paul Ramsey)
• Ensure support for upcoming 9.0 PgSQL release
• (Paul Ramsey)

What is new in version 1.3.5:

• This release fixes an important bug introduced in previous release that broke the ability to use Mapserver LINE layers with PostGIS.

What is new in version 1.3.4:

• This release added an ST_AsGeoJSON() function, PostgreSQL 8.4 support, performance improvements with GEOS 3.1, memory leak fixes, documentation improvements, and more reliable handling of curve types.

Requirements:

• PostgreSQL