Installing PostgreSQL on Linux [CentOS] – A Step by Step Guide

PostgreSQL has earned a strong reputation of being the world’s most advanced open source Relational database. Over the past few years it has seen a sharp rise in popularity as a Tier-1 RDBMS and more and more organizations are embracing PostgreSQL now a days.

Moreover, it’s open-source, free to use, community-driven, without being owned by a single company, standards-compliant, has proven architecture, reliability, data integrity, filled with useful features, and very extensible.

I think as a database professional, its good time to get our hands dirty and learn this amazing technology.

We will install the latest PostgreSQL 12 on CentOS distribution of Linux Server for this demonstration.

Talking about the installation prerequisite, just make sure that you have logged in as a user with sudo privileges on the system. PostgreSQL does not ask for any fancy requirements and a modern Unix-compatible system should be able to run PostgreSQL without any issue. For all the curious souls out there, take a look here for details.

The below guide will take you through the steps used to install PostgreSQL 12 on CentOS:

  1. Install the PostgreSQL Software:

PostgreSQL provides a repository of packages of all supported versions for the most common Linux distributions including CentOS.

So, there are PostgreSQL packages in the base repositories for CentOS already and if this isn’t the version we want, we need to add the specific repo and pull the software from there in order to obtain a specific version.

You can get more information on installed package by running the below command:

$ rpm -qi pgdg-redhat-repo

In order to keep our packages being pulled from the wrong repository or for being overwritten from the wrong repository in future, we are first going to edit the repo file for our distribution.

  • Open the distribution .repo file in vi editor. Use sudo to elevate the permission to run the command.
$ sudo vi /etc/yum.repos.d/CentOS-Base.repo
[user@server ~]$ sudo vi /etc/yum.repos.d/CentOS-Base.repo
[sudo] password for user:
  • Exclude PostgreSQL by appending the following line to both the [base] and [updates] sections. Make sure to put a blank line after the line.
$ exclude=postgresql*
# CentOS-Base.repo
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client.  You should use this for CentOS updates
# unless you are manually picking other mirrors.
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.

name=CentOS-$releasever - Base

#released updates
name=CentOS-$releasever - Updates

#additional packages that may be useful
name=CentOS-$releasever - Extras

#additional packages that extend functionality of existing packages
name=CentOS-$releasever - Plus

-- INSERT --
$ sudo yum -y install
[user@server ~]$ sudo yum -y install
Loaded plugins: fastestmirror
pgdg-redhat-repo-latest.noarch.rpm                                                                                                                                                                                     | 6.5 kB  00:00:00     
Examining /var/tmp/yum-root-GABjzR/pgdg-redhat-repo-latest.noarch.rpm: pgdg-redhat-repo-42.0-11.noarch
Marking /var/tmp/yum-root-GABjzR/pgdg-redhat-repo-latest.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package pgdg-redhat-repo.noarch 0:42.0-11 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

 Package                                                   Arch                                            Version                                             Repository                                                                Size
 pgdg-redhat-repo                                          noarch                                          42.0-11                                             /pgdg-redhat-repo-latest.noarch                                           11 k

Transaction Summary
Install  1 Package

Total size: 11 k
Installed size: 11 k
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : pgdg-redhat-repo-42.0-11.noarch                                                                                                                                                                                            1/1 
  Verifying  : pgdg-redhat-repo-42.0-11.noarch                                                                                                                                                                                            1/1 

  pgdg-redhat-repo.noarch 0:42.0-11                                                                                                                                                                                                           

  • Install PostgreSQL 12:
$ sudo yum install -y postgresql12-server postgresql12-contrib
[user@server ~]$ sudo yum install -y postgresql12-server postgresql12-contrib
Loaded plugins: fastestmirror
Determining fastest mirrors
epel/x86_64/metalink                                                                                                                                                                                                   | 5.3 kB  00:00:00     
 * base:
 * epel:
 * extras:
 * nux-dextop:
 * updates:
base                                                                                                                                                                                                                   | 3.6 kB  00:00:00     
epel                                                                                                                                                                                                                   | 4.7 kB  00:00:00     
extras                                                                                                                                                                                                                 | 2.9 kB  00:00:00     
nux-dextop                                                                                                                                                                                                             | 2.9 kB  00:00:00     
pgdg-common                                                                                                                                                                                                            | 2.9 kB  00:00:00     
pgdg10                                                                                                                                                                                                                 | 3.6 kB  00:00:00     
pgdg11                                                                                                                                                                                                                 | 3.6 kB  00:00:00     
pgdg12                                                                                                                                                                                                                 | 3.6 kB  00:00:00     
pgdg95                                                                                                                                                                                                                 | 3.6 kB  00:00:00     
pgdg96                                                                                                                                                                                                                 | 3.6 kB  00:00:00     
updates                                                                                                                                                                                                                | 2.9 kB  00:00:00     
xrdp                                                                                                                                                                                                                   | 2.9 kB  00:00:00     
(1/20): base/7/x86_64/group_gz                                                                                                                                                                                         | 153 kB  00:00:00     
(2/20): extras/7/x86_64/primary_db                                                                                                                                                                                     | 194 kB  00:00:00     
(3/20): epel/x86_64/updateinfo                                                                                                                                                                                         | 1.0 MB  00:00:00     
(4/20): epel/x86_64/group_gz                                                                                                                                                                                           |  95 kB  00:00:00     
(5/20): epel/x86_64/primary_db                                                                                                                                                                                         | 6.8 MB  00:00:00     
(6/20): base/7/x86_64/primary_db                                                                                                                                                                                       | 6.1 MB  00:00:01     
(7/20): pgdg10/7/x86_64/group_gz                                                                                                                                                                                       |  245 B  00:00:01     
(8/20): nux-dextop/x86_64/primary_db                                                                                                                                                                                   | 1.8 MB  00:00:01     
(9/20): pgdg-common/7/x86_64/primary_db                                                                                                                                                                                | 116 kB  00:00:02     
(10/20): pgdg11/7/x86_64/group_gz                                                                                                                                                                                      |  245 B  00:00:01     
(11/20): pgdg11/7/x86_64/primary_db                                                                                                                                                                                    | 219 kB  00:00:01     
(12/20): pgdg95/7/x86_64/group_gz                                                                                                                                                                                      |  249 B  00:00:00     
(13/20): pgdg12/7/x86_64/primary_db                                                                                                                                                                                    | 135 kB  00:00:00     
(14/20): pgdg96/7/x86_64/group_gz                                                                                                                                                                                      |  249 B  00:00:00     
(15/20): pgdg12/7/x86_64/group_gz                                                                                                                                                                                      |  245 B  00:00:01     
(16/20): pgdg95/7/x86_64/primary_db                                                                                                                                                                                    | 206 kB  00:00:00     
(17/20): pgdg10/7/x86_64/primary_db                                                                                                                                                                                    | 220 kB  00:00:02     
(18/20): pgdg96/7/x86_64/primary_db                                                                                                                                                                                    | 215 kB  00:00:00     
(19/20): updates/7/x86_64/primary_db                                                                                                                                                                                   | 2.9 MB  00:00:00     
(20/20): xrdp/primary_db                                                                                                                                                                                               | 1.8 MB  00:00:02     
Resolving Dependencies
--> Running transaction check
---> Package postgresql12-contrib.x86_64 0:12.3-5PGDG.rhel7 will be installed
--> Processing Dependency: postgresql12-libs(x86-64) = 12.3-5PGDG.rhel7 for package: postgresql12-contrib-12.3-5PGDG.rhel7.x86_64
--> Processing Dependency: postgresql12(x86-64) = 12.3-5PGDG.rhel7 for package: postgresql12-contrib-12.3-5PGDG.rhel7.x86_64
--> Processing Dependency: for package: postgresql12-contrib-12.3-5PGDG.rhel7.x86_64
---> Package postgresql12-server.x86_64 0:12.3-5PGDG.rhel7 will be installed
--> Running transaction check
---> Package postgresql12.x86_64 0:12.3-5PGDG.rhel7 will be installed
---> Package postgresql12-libs.x86_64 0:12.3-5PGDG.rhel7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

 Package                                                          Arch                                               Version                                                         Repository                                          Size
 postgresql12-contrib                                             x86_64                                             12.3-5PGDG.rhel7                                                pgdg12                                             609 k
 postgresql12-server                                              x86_64                                             12.3-5PGDG.rhel7                                                pgdg12                                             5.0 M
Installing for dependencies:
 postgresql12                                                     x86_64                                             12.3-5PGDG.rhel7                                                pgdg12                                             1.6 M
 postgresql12-libs                                                x86_64                                             12.3-5PGDG.rhel7                                                pgdg12                                             369 k

Transaction Summary
Install  2 Packages (+2 Dependent packages)

Total download size: 7.5 M
Installed size: 31 M
Downloading packages:
warning: /var/cache/yum/x86_64/7/pgdg12/packages/postgresql12-12.3-5PGDG.rhel7.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 442df0f8: NOKEY                                                             ] 486 kB/s | 864 kB  00:00:14 ETA 
Public key for postgresql12-12.3-5PGDG.rhel7.x86_64.rpm is not installed
(1/4): postgresql12-12.3-5PGDG.rhel7.x86_64.rpm                                                                                                                                                                        | 1.6 MB  00:00:03     
(2/4): postgresql12-contrib-12.3-5PGDG.rhel7.x86_64.rpm                                                                                                                                                                | 609 kB  00:00:03     
(3/4): postgresql12-libs-12.3-5PGDG.rhel7.x86_64.rpm                                                                                                                                                                   | 369 kB  00:00:00     
(4/4): postgresql12-server-12.3-5PGDG.rhel7.x86_64.rpm                                                                                                                                                                 | 5.0 MB  00:00:03     
Total                                                                                                                                                                                                         1.1 MB/s | 7.5 MB  00:00:06     
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-PGDG
Importing GPG key 0x442DF0F8:
 Userid     : "PostgreSQL RPM Building Project <>"
 Fingerprint: 68c9 e2b9 1a37 d136 fe74 d176 1f16 d2e1 442d f0f8
 Package    : pgdg-redhat-repo-42.0-11.noarch (@/pgdg-redhat-repo-latest.noarch)
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-PGDG
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : postgresql12-libs-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                                  1/4 
  Installing : postgresql12-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                                       2/4 
  Installing : postgresql12-server-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                                3/4 
  Installing : postgresql12-contrib-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                               4/4 
  Verifying  : postgresql12-libs-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                                  1/4 
  Verifying  : postgresql12-contrib-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                               2/4 
  Verifying  : postgresql12-server-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                                3/4 
  Verifying  : postgresql12-12.3-5PGDG.rhel7.x86_64                                                                                                                                                                                       4/4 

  postgresql12-contrib.x86_64 0:12.3-5PGDG.rhel7                                                                         postgresql12-server.x86_64 0:12.3-5PGDG.rhel7                                                                        

Dependency Installed:
  postgresql12.x86_64 0:12.3-5PGDG.rhel7                                                                              postgresql12-libs.x86_64 0:12.3-5PGDG.rhel7                                                                             

  1. Initialize the Database and start PostgreSQL:
  • Initialize the database:
$ sudo /usr/pgsql-12/bin/postgresql-12-setup initdb
[user@server ~]$ sudo /usr/pgsql-12/bin/postgresql-12-setup initdb
Initializing database ... OK
  • Start the PostgreSQL-12 service:
$ sudo systemctl start postgresql-12
[user@server ~]$ sudo systemctl start postgresql-12
[user@server ~]$
  • Configure PostgreSQL to start on boot:
$ sudo systemctl enable postgresql-12
[user@server ~]$ sudo systemctl enable postgresql-12
Created symlink from /etc/systemd/system/ to /usr/lib/systemd/system/postgresql-12.service.
[user@server ~]$
  1. Connect to the instance:

When you install PostgreSQL, a Linux user named postgres  is created by default with superuser privilege. We will use this user to connect to the newly installed PostgreSQL Instance.

  • Let’s change to the postgres user:
$ sudo su - postgres
[user@server ~]$ sudo su - postgres
  • Type psql and press enter. It will take you to the  psql prompt, i.e.  postgres=# . Once you see the psql prompt, rest assured that your installation is correct.
$ psql
-bash-4.2$ psql
psql (12.3)
Type "help" for help.

  • Now, let’s give the postgres role a password 
\password postgres
postgres=# \password postgres
Enter new password: 
Enter it again: 

We are all set now!! This marks the completion of the installation steps for PostgreSQL on Linux.

Next comes configuration of the newly installed PostgreSQL instance as per our requirement. This has been discussed on a separate post here.

3 thoughts on “Installing PostgreSQL on Linux [CentOS] – A Step by Step Guide

  1. Hi ,
    I am getting below error while trying to install postgreSql on Oracle virtual Box OEL6.9

    [oracle@bigdatalite tmp]$ sudo yum -y install
    Loaded plugins: refresh-packagekit, security, ulninfo
    Setting up Install Process
    Cannot open: Skipping.
    Error: Nothing to do
    [oracle@bigdatalite tmp]$


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