title: How to calculate Join cost? I want to know the disk operations?
body: <p>I want some help regarding join processing</p>
  
  <ol>
  <li>Nested Loop Join</li>
  <li>Block Nested loop join</li>
  <li>Merge join</li>
  <li>Hash join</li>
  </ol>
  
  <p>I search but did not find some link which also provide mathematical examples of calculation? </p>
  
  <p>e.g.</p>
  
  <p>Consider the natural join R &amp; S of relations R and S, with the following information about those relations:</p>
  
  <p>Relation R contains 8,000 records and has 10 records per page</p>
  
  <p>Relation S contains 2,000 records and has 10 records per page</p>
  
  <p>Both relations are stored as sorted files on the join attribute</p>
  
  <p>how many disk operations would it take to process the upper four joins?</p>