title: PDO::fetchAll vs. PDO::fetch in a loop
body: <p>Just a quick question.</p>
  
  <p>Is there any performance difference between using PDO::fetchAll() and PDO::fetch() in a loop (for large result sets)?</p>
  
  <p>I'm fetching into objects of a user-defined class, if that makes any difference.</p>
  
  <p>My initial uneducated assumption was that fetchAll might be faster because PDO can perform multiple operations in one statement while mysql_query can only execute one. However I have little knowledge of PDO's inner workings and the documentation doesn't say anything about this, and whether or not fetchAll() is simply a PHP-side loop dumped into an array.</p>
  
  <p>Any help?</p>