First lets do an update before we start installing PostgreSQL

$ yum update

You can install PostgreSQL from CentOS Base repo or can do a search for the latest version and install it based on your needs. Method 1 describes manual setup and Method 2 indicates an install from CentOS base repo

METHOD 1: Manual setup of PostgreSQL

$ vi /etc/yum.repos.d/CentOS-Base.repo

[base] name=CentOS-$releasever - Base mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 exclude=postgresql*

#released updates [updates] name=CentOS-$releasever - Updates mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates #baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 exclude=postgresql*

Go to http://yum.postgresql.org/repopackages.php and check out for the version of PostgreSQL depending on your OS.

Repo URI for CentOS at the time of writing this tutorial: http://yum.postgresql.org/8.4/redhat/rhel-5-i386/pgdg-centos-8.4-3.noarch.rpm

Now, change to your home directory and install PostgreSQL

$ cd ~

$ curl -O http://yum.postgresql.org/8.4/redhat/rhel-5-i386/pgdg-centos-8.4-3.noarch.rpm

$ rpm -ivh pgdg*

METHOD 2: Install from CentOS base repo

$ yum install postgresql84 postgresql84-server postgresql84-contrib

Initialise the service

$ service postgresql initdb ## OR ## /etc/init.d/postgresql initdb Set the runlevel

$ chkconfig postgresql-8.4 on

Start the database service

$ service postgresql-8.4 start

To make modifications of PostgreSQL configuration, go to

$vi /var/lib/pgsql/8.4/data/postgresql.conf

Some of the most common changes that can be made related to PostgreSQL are listening IP address and port

listen_address = '' port 5432