How can I increase the amount of time a phpmyadmin session is valid when running through Plesk?
There is a value you can set in the phpmyadmin config, but I've been told in some cases, a php.ini config overrides it. So, one configuration you can try is opening up /etc/phpmyadmin/config.inc.php. At the end of the file, put:
Replace xx with the amount of seconds you want the session to be valid for. Also, that is the correct phpmyadmin config file to modify when using Plesk (9.2.3).