title: indexes in sql server, internal working and structure of indexes
body: <p>when we create a clustered index <strong>CIX_FirstNames</strong> on a column , say, <strong>FirstNames</strong>, then what actually happens internally in SQL Server?</p>
  
  <p>i have read that clustered indexes create copy of the data.</p>
  
  <p>so, does sql server creates a new index table, <strong>IndexTable</strong> , and copies all the FirstNames from the table into <strong>IndexTable</strong>, and when a firstname is searched, then it displays it from the index table?</p>
  
  <p>is this the actual working of clustered indexes ?</p>