PostgreSQL: The World’s Most Advanced Open Source Relational Database

PostgreSQL is arguably the most advance and powerful opensource enterprise class relational database system. It is the object relational database system and provides the most standard compliant system for the Database designers. It provides the complete support for reliable transactions that is (ACID complaint) where ACID stands for Atomicity, Consistency, Isolation and Durability.

Its advance underlying technology makes it extremely powerful and programmable. Support for concurrency is one of its key feature. It is one of the most important technology you will learn and will greatly affect the way you work with Databases. It is the ultimate RDBM system which will allow you to create complex web apps which works flawlessly even for very large number of users.

1. Download and Install Postgresql from the following link

https://www.postgresql.org/download/

2. Configure

service postgresql initdb
systemctl enable postgresql
systemctl start postgresql

Edit the file /etc/postgresql/8.4/main/pg_hba.conf and replace ident or peer by either md5 or trust, depending on whether you want it to ask for a password on your own computer or not. Then reload the configuration file with:

/etc/init.d/postgresql reload

pg_hba.conf

local   all             all                                     peer
# IPv4 local connections:
host    all             all             127.0.0.1/32            password  
# IPv6 local connections:
host    all             all             ::1/128                 password

3. Create user and database with permissions

sudo -u postgres psql
postgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;