What is postgreSQL?

postgreSQL is an object-relational database management system(ORDBMS) based on postgres. It is an open-source product. It supports a large part of SQL standards and offers many modern features.

• complex queries
• foreign keys
• triggers
• views
• transactional integrity
• multiversion concurrency control

Also, postgreSQL can be extended by the user in many ways, for example by adding new

• data types
• functions
• operators
• aggregate functions
• index methods
• procedural languages

There is a extension called postGIS to the postgreSQL. postGIS supports for geographical objects to the postgreSQL database, allowing it to be backend database for geographic information systems(GIS).

And because of the liberal license, postgreSQL can be used, modified, and distributed by everyone free of charge for any purpose, be it private, commercial, or academic.

• Just search in your cache for postgreSQL by typing following in command line

apt-cache search postgresql

• Then list latest version of the postgresql. For an example, we are going to install postgresql-8.2. To install type following ..

apt-get install postgresql-8.2

• During installation it creates a user called “postgres”. That user has permission work with postgresql database.

• First you have to log as postgres user

• Initially there are three databases

postgres
template0
template1

• To connect postgres database

$ psql postgres

• To get help with SQL command

postgres=# \h

• To get help with psql command

postgres=# \?

• Official web site for postgreSQL

postgreSQL.org

• Online Documentation for postgreSQL

PostgreSQL Documentation

• Information about postGIS

postGIS home