title: Retrieve 50 random records from a Mysql database table (large data set)
body: <p>I need to retrieve a number of random records from a table. The table contains about <strong>100000</strong> records.</p>
  
  <p>The records must not be consecutive and performance is important.</p>
  
  <p>I tried "<code>order by rand()</code>" but the performance is bad ( <strong>~3</strong> seconds)</p>