PostGIS - ArchWiki

# PostGIS

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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 has not, please refer to the PostgreSQL page.

## Installing PostGIS

Install the postgis package.

## Installing PostGIS Extension

Since PostgreSQL 9.1, 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;
    CREATE EXTENSION postgis_topology;
    CREATE EXTENSION fuzzystrmatch;
    CREATE EXTENSION postgis_tiger_geocoder;

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

- upgrade postgis extension

    $ psql

    ALTER EXTENSION postgis UPDATE TO "2.1.0";

- 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 https://www.postgis.net/docs/postgis_installation.html#hard_upgrade for specific commands.

## Creating a Template PostGIS Database

- Become the postgres user.

    $ su
    # su - postgres

- If you have not 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

- 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-2.1/" depending on the installation. (Below is for default postgis 2.1 installation)

    $ psql -d template_postgis -f /usr/share/postgresql/contrib/postgis-2.1/postgis.sql
    $ psql -d template_postgis -f /usr/share/postgresql/contrib/postgis-2.1/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 has not put out a stable release with this yet. It is in 2.1.0rc1, though. The bug-report is https://trac.osgeo.org/postgis/ticket/2213

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

Category:

- Database management systems