title: Delete large number of keys in Redis
body: <p>I have a large number of simple keys to delete from Redis with a prefix and I am trying to find the most efficient way to do this atomically inside a transaction with Lua script:</p>
  
  <ol>
  <li>Iterate with SCAN and DEL keys?</li>
  <li>Iterate with SCAN and EXPIRE each key?</li>
  <li>Iterate with SCAN and UNLINK keys?</li>
  </ol>
  
  <p>Which of the above is the recommended way to proceed? Shall I have a different approach - like using a hash and multiple keys inside hash? Would any of the above be any problem in case of Redis cluster?</p>