title: redis key-value what the limitation of key?
body: <pre><code>set "as";b 1 is error 
  key:  "as";b
  value:   1
  </code></pre>
  
  <p>what is the naming rule of key?</p>
  
  <p>Redis uses SDS to implement  string. Book says SDS can contain any construction of string </p>