title: redis how to limit the return number of KEYS command?
body: <p>I get values with  "KEYS p_*" command in redis.</p>
  
  <p>But with "KEYS p_*" , if the redis has millions of keys,I will get too many 
  values and bad performence.</p>
  
  <p>So can I just get 100 values with "KEYS p_*" command?</p>