In my local development Ubuntu box I use MySQL and phpmyadmin to work with the database.
Whenever phpmyadmin is idle for 1440 secs (24min) the session expires. I lose m
Add this line to /config.inc.php:
$cfg['LoginCookieValidity'] = 36000;
In /setup/lib/index.lib.php
$cf->getValue('LoginCookieValidity') > 36000;
If you don't already have a .htaccess file for your phpMyAdmin site, create one, and add the following line to override the default PHP session timeout:
php_value session.gc_maxlifetime 36000
I would not recommend altering this value in your main php.ini file, as it will allow a ridiculously long session timeout for all your PHP sites.
source: http://www.sitekickr.com/blog/increase-phpmyadmin-timeout/