From ArchWiki
Revision as of 17:30, 6 February 2014 by Santagada (talk | contribs) (from the postgis install docs: you need fuzzystrmatch to use tiger geocoder)
Jump to: navigation, search

PostGIS adds support for geographic objects in the PostgreSQL database. This document describes the process for installing PostGIS and creating a template PostGIS database. It is assumed that PostgreSQL has been installed. If it hasn't, please refer to the PostgreSQL page.

Installing PostGIS

  • Install PostGIS.
$ su
# pacman -S postgis

Installing PostGIS Extension

Since [[PostgreSQL 9.1][1]], the preferred approach is to install PostGIS and enable postgis extension for each spatial database.

$ psql

-- verify available extensions
SELECT name, default_version,installed_version 
FROM pg_available_extensions WHERE name LIKE 'postgis%' ;

-- install extension for spatial database mygisdb
\c mygisdb
CREATE EXTENSION postgis_topology;
CREATE EXTENSION fuzzystrmatch;
CREATE EXTENSION postgis_tiger_geocoder;

You don't need to do the below "Creating a Template PostGIS Database" step if you use PostGIS extension.

  • upgrade postgis extension
$ psql

  • migrate spatial database created with postgis_template

Dump and drop the spatial database, re-create a spatial database with extension, and restore the dumped database. Follow for specific commands.

Creating a Template PostGIS Database

  • Become the postgres user.
$ su
# su - postgres
  • If you haven't created a superuser for accessing PostgreSQL, you may want do that now. You will be prompted for granting permissions to that user.
$ createuser [username]
  • Create a new database called "template_postgis".
$ createdb -O [username] template_postgis -E UTF-8
  • PostGIS requires the pl/pgSQL language to be installed on a database.
$ createlang plpgsql template_postgis
  • Load the PostGIS spatial types for PostgreSQL and spatial reference systems. "postgis.sql" and "spatial_ref_sys.sql" are part of the installation of PostGIS, and may reside somewhere else besides "/usr/sharepostgresql/contrib/postgis-1.5/" depending on the installation. (Below is for default postgis 1.5 installation)
$ psql -d template_postgis -f /usr/share/postgresql/contrib/postgis-2.0/postgis.sql
$ psql -d template_postgis -f /usr/share/postgresql/contrib/postgis-2.0/spatial_ref_sys.sql
  • Make it a real template.
$ psql

UPDATE pg_database SET datistemplate = TRUE WHERE datname = 'template_postgis';

Creating a PostGIS Database From the Template

  • It's common practice to reserve a bare template for creating new PostGIS databases. As a PostgreSQL superuser, the following command will create a new database:
$ createdb -T template_postgis [new_postgis_db]

More Resources

For additional resources concerning PostGIS, check out the PostGIS Documentation.

PostGIS failing with json_tokener_error

This happends when adding postgis as an extension. The libjson-c package has changed, and PostGIS hasn't put out a stable release with this yet. Its in 2.1.0rc1, though. The bug-report is

The fix is to download the postgis PKGBUILD and then change the version to '2.1.0rc1'. Don't forget to change the sha256sum.