title: techniques for bulk data processing
body: <p>I'm looking for a technique to do the following and I need your advices.
  I have a huge (really )table with registration ids and I need to send messages to these ID owners. I cant send the message to many recipients at once, this needs to be proceeded one by one. So I would like to have a script(php)  which can run in many parallel instances (processes) by getting some amount from db and processing it. In other words every process needs to work with a particular range of data. I would like also to stop each process and to be able to continue message sending from the stopped user to another set of users who didnt get the message yet. 
  If it's possible? Any tips and advices are welcome.</p>