Install PostgreSql and PostGIS On Ubuntu Server

  There is an article[1] for installing PostgreSQL on Ubuntu. [2] actually is a even better one if you want to install PostgreSQL and PostGIS at the same time.

  In order to use PostGIS in database, you need to execute two commands below[3] in every database that you want to have PostGIS extension.

-- Enable PostGIS (includes raster)
CREATE EXTENSION postgis;
-- Enable Topology
CREATE EXTENSION postgis_topology;

Reference:

[1]https://www.digitalocean.com/community/articles/how-to-install-and-use-postgresql-on-ubuntu-12-04

[2]http://trac.osgeo.org/postgis/wiki/UsersWikiPostGIS21UbuntuPGSQL93Apt

[3]http://postgis.net/install/