Open the 'config.inc.php' file located inside '/etc/phpmyadmin/config.inc.php' and add the following line:
$cfg['ExecTimeLimit'] = 0;
This will remove any time constraint in phpMyAdmin for database import.
Now make the following changes in your 'php.ini' file which is located at '/etc/php5/apache2/php.ini.' You will have to sudo and open your editor to make/commit the changes:
post_max_size = 750M upload_max_filesize = 750M max_execution_time = 300 max_input_time = 540 memory_limit = 1000M
Now finally restart your Apache Web Server:
sudo service apache2 restart