gistfile1.php

<?php
for ($i=1; $i <= 10; $i++) {

$start = microtime(true);

for ($ii=0; $ii < 50; $ii++) {

  //Pick 8 random tids to search for
  $tids = array();
  for ($iii=0; $iii < 7; $iii++) {
    $tids[] = rand(500, 1000000);
  }

  //Stuff the randomly selected tids into an array compatible with db_query
  $args = array(
    ":tids" => $tids
  );

  //Get a ranked list of the 5 nodes which have the most matches
  $query = db_query("SELECT nid,count(tid)
    FROM taxonomy_index
    WHERE tid
    IN (:tids)
    GROUP BY nid
    ORDER BY count(tid) DESC
    LIMIT 5", $args);

  $result = $query->fetchAll();
}
print "Run $i: " . round(microtime(true) - $start, 3) . ' seconds' . "\n";
}