Log All Queries with Execution Time for Codeigniter 3.x

1. Set the log_threshold to 2 in applications/config/config.php file

$config['log_threshold'] = 2;
or
$config['log_threshold'] = array(2);

2. Set the enable_hooks to true in applications/config/config.php file

$config['enable_hooks'] = true;

3. Then Open up your hooks.php file in applications/config folder and add the following code in it

$hook['post_controller'][] = array(
    'class' => 'Log_Query', 
    'function' => 'run',
    'filename' => 'Log_query.php',
    'filepath' => 'hooks'
);

4. Now add applications/hooks/Log_query.php file in the repository to your codeigniter applications/hooks folder.