title: Running a Cron job continuously
body: <p>sorry if this question has been asked before, however I could not find anything relevant when searching.</p>
  
  <p>I currently have a PHP script which polls a database for the next record which is has not been updated. My question is this: If I then update the database to show that the record is processing while the cron job is running (which takes approx 30 seconds), and the cron job is set to run every second, at second 1 the cron job runs, but will this job wait to complete before the cron job runs for the second time, or will it run at second 2?</p>
  
  <p>Thanks</p>