Actually, since he was effectively doing SELECT * ... it still has to go pull the rows from the table after seeking the index.  This likely isn't a huge problem though.<p>To prevent going back to the table in this case, you'd either need the index I mentioned to be the primary key, or a construct like INCLUDE (which mysql appears to lack).<p>See <a href="http://msdn.microsoft.com/en-us/library/ms188783.aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/ms188783.aspx</a>