Upgrading PostgreSQL on Ubuntu

October 3, 2016

I recently started using Ubuntu Linux on my main development machine. That means that my PostgreSQL database is running under Ubuntu, as well. I’ve written guides to upgrading PostgreSQL using Homebrew in the past, but the upgrade process under Ubuntu was much smoother.

These steps are assuming that you use Ubuntu 16.04 LTS, and PostgreSQL 9.6 is already installed via apt.

Stop the postgresql service.
```
$ sudo service postgresql stop
```
Move the newly-created PostgreSQL 9.6 cluster elsewhere.
```
$ sudo pg_renamecluster 9.6 main main_pristine
```
Upgrade the 9.5 cluster.
```
$ sudo pg_upgradecluster 9.5 main
```
Start the postgresql service.
```
$ sudo service postgresql start
```

Now, when running pg_lsclusters, you should see something like the following:

9.5 main          5434 online postgres /var/lib/postgresql/9.5/main          /var/log/postgresql/postgresql-9.5-main.log
9.6 main          5432 online postgres /var/lib/postgresql/9.6/main          /var/log/postgresql/postgresql-9.6-main.log
9.6 main_pristine 5433 online postgres /var/lib/postgresql/9.6/main_pristine /var/log/postgresql/postgresql-9.6-main_pristine.log

Verify everything is working as expected, then feel free to remove the 9.5/main and 9.6/main_pristine clusters ( pg_dropcluster).

These cluster commands may be available in other distros, but I haven’t been able to check them. YMMV. Good luck!