Introduction {#h-introduction} In this tutorial, we learn how to install PostgreSQL 13 on Ubuntu 20.04 (Focal Fossa). PostgreSQL, or usually called Postgres, is an open-source object-relational database management system (ORDBMS) with an emphasis on extensibility and standards compliance. PostgreSQL is ACID-compliant and transactional. It is developed by PostgreSQL Global Development Group (PGDG) that consists of many companies and individual contributors. PostgreSQL released under the terms of PostgreSQL license. PostgreSQL 13 was released on 18 October 2018. Major enhancements in PostgreSQL 13 includes: _ Continued Performance Gains _ Administration Optimizations (vacuuming, replication slots) _ Application Development Conveniences _ Security Enhancements ## Prerequisites {#h-prerequisites} This tutorial assume you already satisfy the following requirements: _ A machine with fresh install of Ubuntu Server 20.04. It can be A virtual machine locally using Virtualbox, VMWare workstation or VMWare Fusion, KVM, Xen, or a virtual machine in the cloud like [DigitalOcean][1] or [Linode][2]. _ A non-root user with sudo privileges or a root user access. If you’re usig root user remove sudo from each command on this tutorial. ## Step 1 — Update Base Systems {#h-step-1-update-base-systems} Since this is a fresh install of Ubuntu Server 20.04, before we install PostgreSQL 13, let’s update our system to the latest update. sudo apt-get update sudo apt-get -y upgrade After we upgrade our base system, now it’s time to install PostgreSQL 13. Since Ubuntu 20.04 doesn’t have PostgreSQL 13 in [its repository][3], we need to add oficial PostgreSQL repository so we can install PostgreSQL 13. ## Step 2 — Import Repository Signing Key {#h-step-2-import-repository-signing-key} The PostgreSQL team is using GPG to sign downloadable packages from the PostgreSQL website. We add PostgreSQL public GPG key so apt can verify that packages downloaded from PostgreSQL repository are not tampered or corrupt. Add PostgreSQL GPG public key using the command below. wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add - You should get OK output for command above. If you got the different output, you need to fix the error first before continue to the next step. ## Step 3 — Add PostgreSQL 13 repository {#h-step-3-add-postgresql-13-repository} After adding PostgreSQL release keys, we create a new repository configuration for PostgreSQL using the command below. echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" | sudo tee /etc/apt/sources.list.d/postgresql-pgdg.list > /dev/null Refresh apt metadata using the command below. sudo apt-get update ## Step 4 — Install PostgreSQL 13 on Ubuntu 20.04 {#h-step-4-install-postgresql-13-on-ubuntu-20-04} We’re ready to install PostgreSQL 13. Use the command below to install PostgreSQL 13 on Ubuntu 20.04. sudo apt-get install postgresql-13 Alternative method to install PostgreSQL 13 on Ubuntu 20.04 is using apt command sudo apt install postgresql-13 Only 4 steps needed to install PostgreSQL 13 on Ubuntu 20.04. We learn how to check and verify and managing PostgreSQL 13 installation in the next few sections. ## Verify PostgreSQL 13 Installation on Ubuntu 20.04 {#h-verify-postgresql-13-installation-on-ubuntu-20-04} We can check PostgreSQL 13 packages that already installed using the command below. dpkg -l | grep postgresql ## Check PostgreSQL 13 Listening Ports {#h-check-postgresql-13-listening-ports} By default, PostgreSQL listens on port 5432. We can use netstat to check whether there is a process listening on port 5432. sudo netstat -naptu | grep 5432 Another method is to check whether there is a process named postgres listening on a port. sudo netstat -naptu | grep postgres Alternative to netstat, We can use ss command below to check whether there is a process listen on PostgreSQL default port 5432. sudo ss -atnp | grep 5432 We can also use ss to check whether there is a process named postgres listening on a port. sudo ss -atp | grep postgres The last output above shows there is also a connection to ephemeral UDP port from local. According to this thread on PostgreSQL mailing lists, this is a PostgreSQL stats collector that uses UDP to send and receive stats data locally. ## Checking PostgreSQL Process {#h-checking-postgresql-process} We can ue ps command to check what processes currently running with name contain postgres. ps -aux | grep postgres Check PostgreSQL 13 resource usage like CPU and memory usingtop command. top -u postgres ## Managing PostgreSQL 13 Services on Ubuntu 20.04 {#h-managing-postgresql-13-services-on-ubuntu-20-04} Check postgres service status using command below. sudo service postgresql status We can also use systemctl command to check PostgreSQL service status. sudo systemctl status postgresql Using both commands above you see active (exited) on the Active: line. This happens because systemd doesn’t know the status of each PostgreSQL cluster running on the instance. One instance/installation of PostgreSQL can run multiple clusters of PostgreSQL. We can check, list of PostgreSQL clusters running on our machine using the command below. pg_lsclusters There is one cluster running on our machine. The cluster named main running PostgreSQL 13. To check this cluster service status, we can use the command below. sudo service postgresql@13-main status As an alternative to service, we can use systemctl to check this cluster status. sudo systemctl status postgresql@13-main Stop PostgreSQL service using the command below. sudo systemctl stop postgresql Start PostgreSQL service using the command below. sudo systemctl start postgresql Restart PostgreSQL service using the command below. sudo systemctl restart postgresql Reload PostgreSQL service using the command below. sudo systemctl reload postgresql ## Connect to PostgreSQL using psql {#h-connect-to-postgresql-using-psql} Now let’s connect to the PostgreSQL 13 server using psql client application. By default, postgres create system user named postgres. There is also role in postgresql database named postgres wth superuser permission. Switch to postgresql user. sudo su - postgres After switching to postgres user, we can connect using psql command. To list all databases in PostgreSQL we can use \l command. To list all users in PostgreSQL we can use \du command. To exit from psql we can use \q command. To exit from postgres user type exit or CTRL+D ## Change postgres User Password {#h-change-postgres-user-password} Now we’re on our own linux user. Let’s try to login to localhost or 127.0.0.1. $ psql -U postgres -W -h 127.0.0.1 Password for user postgres: It prompts for a password. However, since we haven’t set any password, let’s leave it empty. We get the error message below. psql: fe_sendauth: no password supplied Since we cannot login without providing password, we set new password for postgres user. Change user to postgres user like shown above and use psql to connect to PostreSQL. After logging in, type \password. Enter new password and confirmation password for user postgres. When we login again to localhost or 127.0.0.1 and provide a password, we can log in successfully. ## Uninstall PostgreSQL 13 from Ubuntu 20.04 {#h-uninstall-postgresql-13-from-ubuntu-20-04} In this section, we learn how to uninstall PostgreSQL 13 and its dependencies on Ubuntu 20.04 completely. Please be careful when running steps in this section since this will stop your PostgreSQL database server. Use the command below to uninstall all PostgreSQL 13 packages, both server, and client. sudo apt-get remove postgresql-13 \ postgresql-client-13 \ postgresql-client-common \ postgresql-common Remove the PostgreSQL data directory using the command below. rm -rf /var/lib/postgresql/ Remove PostgreSQL 13 configuration directories using the command below. rm -rf /etc/postgresql rm -rf /etc/postgresql-common ## PostgreSQL 13 References {#h-postgresql-13-references} You can follow the links below to learn more about PostgreSQL 13 from PostgreSQL official documentation. _ [Release Notes of PostgreSQL 13][4] _ [PostgreSQL 13 release announcement][5] * [Documentation of PostgreSQL 13][6] ## Conclusion {#h-conclusion} In this tutorial, we learn how to install PostgreSQL 13 on ubuntu 20.04. We also learn managing PostgreSQL services, using tools like netstat, ss, ps, and top to check PostgreSQL service. After that, we learn how to connect to PostgreSQL 13 server using psql client, changing postgres superuser password, and in the end, we learn how to uninstall PostgreSQL 13. I hope this is useful for initiating your journey to PostgreSQL 13. [1]: https://htdj.in/doreff [2]: https://htdj.in/linodereff [3]: https://packages.ubuntu.com/xenial/postgresql [4]: https://www.postgresql.org/docs/13/release.html [5]: https://www.postgresql.org/about/news/postgresql-13-released-2077/ [6]: https://www.postgresql.org/docs/13/index.html