How to upgrade PostgreSQL to a newer version

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Stratos Matzouranis

The journey began in 2008 where I officially started working in the field of IT (IT). Starting the first semester of school I realized a special attraction towards databases and automation. I have been involved with databases such as Microsoft SQL Server / Oracle Database, data analysis and automations using the command line (CLI), Visual Basic for Applications and Python. Through years of experience I have developed these capabilities so that I can make my life easier. For me, the purpose of every IT guy and every office worker is to have the knowledge so that through tools he can work a little but produce a lot. Through this his website DataPlatform.gr I try to offer knowledge and propose solutions to everyday problems.

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Latest posts by Stratos Matzouranis (see all)

• How to upgrade PostgreSQL to a newer version - 23 September 2026
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Migrating PostgreSQL from an older version to a newer one is a critical maintenance process that requires care to ensure data integrity. In this article, we will walk you through the steps to smoothly upgrade a database from PostgreSQL 11 to PostgreSQL 14 using the official tool. pg_upgrade.

Preparation and Installation

First, we proceed to install the necessary server and contrib packages of the new version on the system and initialize the new data directory:

sudo yum install -y postgresql14-server postgresql14-contrib
sudo /usr/pgsql-14/bin/postgresql-14-setup initdb

Before proceeding with any transfer or control action, it is necessary to ensure that the current database is completely inactive by stopping the version 11 service:

sudo systemctl stop postgresql-11

Compatibility Check (Dry Run)

We move to the postgres working directory and execute pg_upgrade accompanied by the parameter --checkIn this way, the tool performs a simulation to identify any incompatibilities, missing extensions or security labels that may hinder the process:

su postgres
cd /var/lib/pgsql
/usr/pgsql-14/bin/pg_upgrade \
  --old-bindir=/usr/pgsql-11/bin \
  --new-bindir=/usr/pgsql-14/bin \
  --old-datadir=/var/lib/pgsql/11/data \
  --new-datadir=/var/lib/pgsql/14/data \
  --check

It is common for them to burst during testing. extensions that have not been installed in the latest version as well as users who use them, e.g. with security label but also tables that have them, e.g. for data masking.

Performing the Upgrade

Once the preventive check is completed successfully and there are no errors, we proceed to the normal execution of the upgrade by removing the --check:

cd /var/lib/pgsql
/usr/pgsql-14/bin/pg_upgrade \
  --old-bindir=/usr/pgsql-11/bin \
  --new-bindir=/usr/pgsql-14/bin \
  --old-datadir=/var/lib/pgsql/11/data \
  --new-datadir=/var/lib/pgsql/14/data

In case any unexpected issue arises during the process, we can examine the log with the command:

tail -n 30 pg_upgrade_utility.log

Activating the new Version

Once the process is complete, we activate and start the new PostgreSQL 14:

sudo systemctl enable postgresql14
sudo systemctl start postgresql14

Next, we perform the statistics refresh process:

/usr/pgsql-14/bin/vacuumdb --all --analyze-in-stages

Cleaning Old Data

After confirming that everything is working perfectly and our applications are connecting normally to the new database, we can permanently delete the old version files to free up disk space:

./delete_old_cluster.sh

Sources:

• PostgreSQL 18.4 Documentation