 <p>Unfortunately, that's does not change anything in me most common cases.</p> <p>Excellent response on which cases are improved : <a href="http://stackoverflow.com/questions/34488/does-limiting-a-query-to-one-record-improve-performance">Does limiting a query to one record improve performance</a></p> <p>And for your case, this article is about offest/limit performances : <a href="http://explainextended.com/2009/10/23/mysql-order-by-limit-performance-late-row-lookups/" rel="nofollow">http://explainextended.com/2009/10/23/mysql-order-by-limit-performance-late-row-lookups/</a></p>