title: Super-columns in Cassandra
body: <p>I must do 5M (5 000 000) super-columns, or ~25M (5M * 5) regular composite-key columns.
  Alternatively I need to use ordered partitioner.</p>
  
  <p>What is exact downside of too many super columns? 
  and why I should avoid them, 
  because if i do composite keys, it is "home-made" super column, and all keys will be still there.</p>