title: PDO Sqlite blocking with multiple writes
body: <p>I'm making a simple logging class that logs messages to a sqlite database using php's pdo extension. It is logging correctly but intermittently slowly. When I load the page it logs quickly, but if a second page is loaded at nearly the same time, it sometimes hangs.</p>
  
  <p>Looking at a profile from XDEBUG, it looks like the prepare and execute statements are sometimes taking very little time, but sometimes taking longer. When they are longer, they are always very close to a multiple of a second (1000, 1001 or 2001 milliseconds for example).</p>
  
  <p>I've tried different combinations of using begin transaction or not and PDO::ATTR_PERSISTENT.</p>
  
  <p>Any suggestions?</p>