title: What is the difference between hashing and indexing?
body: <p>I have studied hashing in DBMS (extensible, linear) and about Indexing in DBMS (sparse, dense, indexes based on secondary key, etc.), but I am unable to understand what the difference is between Hashing and Indexing.  Are these two techniques used together or is just either used?  I am confused because the purpose of both techniques seem to be to enable us to retrieve the data quickly, so I think either should be sufficient.</p>
  
  <p>Can anyone clarify the difference?</p>