Log all SQL queries made from Wordpress

functions.php

<?php 
// Include this on your functions.php

function log_sql_queries($text_query){
    /* //Uncomment me if you want a lot of info about where the sql query comes from and what action started it off
    $traces = debug_backtrace();
    foreach ($traces as $tobj => $trace) {
        if($trace['function'] == 'do_action'){
            $args = $trace['args'];
        }
        error_log("TRACE:$i:"  . $trace['function'] . print_r($args,1));
        $i++;
    }
    */
    error_log("INFO:SQL: " . $text_query);
    return $text_query;
}
add_filter( 'posts_request', 'log_sql_queries', 500 );