$pdo = new PDO("mysql:host=localhost;dbname=articlem_split", '***', '***');
$pdo->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);

$uresult = $pdo->query("SELECT * FROM users");

while ($row = $uresult->fetch(PDO::FETCH_ASSOC)) {
   echo $row['username'] . PHP_EOL;
}

echo memory_get_peak_usage();