title: Ejabberd mod_mam error
body: <p>I am using ejabberd 17.01 at ubuntu server also using mysql . I can see offline messages in table  'spool' and last activity in 'last' table . Bu cant see chatting messages. What is wrong i didnt understand ? i check all the tables but there is no saved data !</p>
  
  <p>Thank you  </p>
  
  <p>ejabberd.yml</p>
  
  <pre><code>mod_mam:
    default: always
    iqdisc: one_queue
    request_activates_archiving: true
    assume_mam_usage: true
    cache_size: 1000
    cache_life_time: 3600
    db_type: sql
  </code></pre>