How to Install PostgreSQL on Ubuntu 26.04

PostgreSQL is an open-source, object-relational database management system known for its reliability, feature set, and standards compliance. It is widely used in production environments ranging from small applications to large-scale data warehouses.

This guide explains how to install PostgreSQL 18 on Ubuntu 26.04, set up roles and authentication, and configure remote access.

Prerequisites #

To follow this guide, you need to be logged in as a user with sudo privileges .

Installing PostgreSQL on Ubuntu 26.04 #

The default Ubuntu 26.04 repositories include PostgreSQL 18.

Start by updating the local package index:

sudo apt update

Install the PostgreSQL server and the contrib package, which provides several additional features:

sudo apt install postgresql postgresql-contrib

Once the installation is completed, the PostgreSQL service starts automatically. Use the psql tool to verify the installation by connecting to the PostgreSQL server and printing its version :

sudo -u postgres psql -c "SELECT version();"

                                                              version
----------------------------------------------------------------------------------------------------------------------------------
 PostgreSQL 18.3 (Ubuntu 18.3-1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 15.2.0-14ubuntu1) 15.2.0, 64-bit
(1 row)

PostgreSQL has been installed and is ready to use.

PostgreSQL Roles and Authentication #

Database access in PostgreSQL is managed through roles. A role can represent a database user or a group of database users.

PostgreSQL supports several authentication methods . The most commonly used are:

• Trust lets a role connect without a password, as long as the conditions in pg_hba.conf are met.
• Password lets a role connect by providing a password. Passwords can be stored as scram-sha-256 or md5.
• Ident is supported on TCP/IP connections. It obtains the client’s operating system username, with optional mapping.
• Peer works like Ident, but for local connections only.

PostgreSQL client authentication is defined in pg_hba.conf. By default, PostgreSQL uses the peer authentication method for local connections.

The postgres user is created automatically during installation. It is the superuser for the PostgreSQL instance, equivalent to the MySQL root user.

To log in to the PostgreSQL server as the postgres user, use the sudo command:

sudo -u postgres psql

You can also switch to the user first:

sudo su - postgres
psql

To exit the PostgreSQL shell, type:

\q

Creating a Role and Database #

Only superusers and roles with the CREATEROLE privilege can create new roles.

The following example creates a role named john, sets a password for the role, and creates a database named johndb owned by that role:

1. Create a new PostgreSQL role:

   Terminal

   sudo -u postgres createuser john

2. Set a password for the role:

   Terminal

   sudo -u postgres psql

   sql

   ALTER ROLE john WITH ENCRYPTED PASSWORD 'strong_password';

   Use a real password here. Do not store it in shell history, scripts, or version control.

3. Create a new database owned by that role:

   Terminal

   sudo -u postgres createdb johndb --owner=john

Because john owns the database, it can create objects in the default public schema without additional grants.

Enabling Remote Access #

By default, PostgreSQL only listens on localhost (127.0.0.1).

To allow remote connections, open the PostgreSQL configuration file:

sudo nano /etc/postgresql/18/main/postgresql.conf

Find the listen_addresses line in the CONNECTIONS AND AUTHENTICATION section and set it to '*' to listen on all interfaces:

listen_addresses = '*'

Save the file and restart the PostgreSQL service:

sudo systemctl restart postgresql

Verify that PostgreSQL is now listening on all interfaces:

ss -nlt | grep 5432

LISTEN  0        244              0.0.0.0:5432           0.0.0.0:*
LISTEN  0        244                 [::]:5432              [::]:*

The next step is to configure which hosts are allowed to connect by editing pg_hba.conf:

sudo nano /etc/postgresql/18/main/pg_hba.conf

Add rules at the bottom of the file. Some examples:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# Allow jane to connect to all databases from anywhere using a password
host    all             jane            0.0.0.0/0               scram-sha-256

# Allow jane to connect only to janedb from anywhere
host    janedb          jane            0.0.0.0/0               scram-sha-256

# Allow jane to connect from a trusted host without a password
host    all             jane            192.168.1.134           trust

Reload PostgreSQL to apply the changes:

sudo systemctl reload postgresql

Finally, open port 5432 in the firewall. To allow access from a specific subnet:

sudo ufw allow proto tcp from 192.168.1.0/24 to any port 5432

Conclusion #

We have shown you how to install PostgreSQL 18 on Ubuntu 26.04 and covered the basics of roles, authentication, and remote access. For more details, consult the PostgreSQL 18 documentation .

About the authors

Dejan Panovski

Dejan Panovski is the founder of Linuxize, an RHCSA-certified Linux system administrator and DevOps engineer based in Skopje, Macedonia. Author of 800+ Linux tutorials with 20+ years of experience turning complex Linux tasks into clear, reliable guides.

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