medir a diferença de microtempo;-) Eu iria com a consulta única, porém, menos conexões, menos tempo de espera e é projetado para lidar com esse tipo de coisa.
http://www.phpjabbers.com/measuring-php -page-load-time-php17.html
<?php
$time = microtime();
$time = explode(' ', $time);
$time = $time[1] + $time[0];
$start = $time;
?>
"SELECT COUNT( * ) AS
FROM (
SELECT users.UID, cnumber
FROM users
JOIN identity ON users.UID = identity.UID
WHERE 'abc'
IN (google, facebook, twitter, linkedin)
) AS userfound
JOIN jobs ON userfound.cnumber = jobs.cnumber
WHERE JID = 24";
if(resultfromquery == 1)
//Some code here
else
//Some code here
<?php
$time = microtime();
$time = explode(' ', $time);
$time = $time[1] + $time[0];
$finish = $time;
$total_time = round(($finish - $start), 4);
echo 'Page generated in '.$total_time.' seconds.';
?>
