title: number of rows in big table
body: <pre><code>SELECT COUNT(*) FROM BigTable_1
  </code></pre>
  
  <p>Which way I should to use to get number of rows in table if I have more than 1 billion of rows?</p>
  
  <p>UPDATE: For example, if we have 'a timeout problem' with the query above is there any way to optimize it?  How to do it quicker?</p>