title: What can cause bad SQL server performance?
body: <p>Every time I find out that the performance of data retrieval from my database is slow. I try to figure out which part of my <strong>SQL query</strong> has the problem and I try to optimize it and also add some <strong>indexes</strong> to the table. But this does not always solve the problem.</p>
  
  <p>My question is : </p>
  
  <p>Are there any other tricks to make SQL server performance better?</p>
  
  <p>What are the other reason which can make SQL server performance worse?</p>