For users with a large database and shell access, it is much quicker to update the database from the command line.

I recommend modifying Knowledge Base Updating 3.2.x

From:

9. Follow the steps to update the database and let that run to completion.

To:

9. Follow the steps to update the database and let that run to completion.^*

*If you have shell access to your server, you may wish to update via the command line interface. From your board's root, execute the following command: php bin/phpbbcli.php --safe-mode db:migrate.