title: How do NULL values affect performance in a database search?
body: <p>In our product we have a generic search engine, and trying to optimze the search performance. A lot of the tables used in the queries allow null values. Should we redesign our table to disallow null values for optimization or not?</p>
  
  <p>Our product runs on both <code>Oracle</code> and <code>MS SQL Server</code>.</p>