title: where to create index on large table?
body: <p>I'm using Oracle 11g. I have table with hundreds of thousands of records.</p>
  
  <p>My Query :</p>
  
  <pre><code>Select a1,a2,..... n 
  from tbl 
  where a1=val1 and a2=val2 and a3=val3 and a4=val4 and a5=val5
  </code></pre>
  
  <p>To improve query performance in where condition for which column I have to create index?</p>