title: XML vs. MySQL direct query performance
body: <p>What, if any, is the performance overhead of using XML as the interface between a Php application (A) and a MySQL database via another Php application (B), rather than direct querying from Php application (A) to the database?</p>
  
  <p>How much will this change between application (A) and the database being on the same server, and being on separate servers?   </p>