title: How to query dynamoDB without using hashKey
body: <p>I have a dynamoDB table with two attributes:</p>
  
  <hr>
  
  <p>A: primary partition key</p>
  
  <p>B: primary sort key</p>
  
  <hr>
  
  <p>I want to query this table using attribute B since I don't know the value of A. Is it possible to do so?</p>
  
  <p>Is it possible to make B as GSI (global secondary index), how to do and query the table using B, since B is already a sort key.</p>