title: SQL Server NUMERIC/DECIMAL precision vs storage
body: <p>Considering what <a href="http://msdn.microsoft.com/en-us/library/ms187746.aspx">MSDN</a> states regarding SQL Server 2008 R2 storage of NUMERIC/DECIMAL precision.</p>
  
  <blockquote>
    <p>Precision of 1 to 9 is 5 bytes<br>
    Precision of 10 to 19 is 9 bytes</p>
  </blockquote>
  
  <p>So if my business case logically requires a data type with 2 decimal places and a precision of 5 digits it makes no actual performance or storage difference if I define it as <strong>NUMERIC(5, 2)</strong> or <strong>NUMERIC(9, 2)</strong>.</p>
  
  <p>One considering I'm intentionally ignoring is the implied check constraint as I'd most likely put an actual check constraint on the column limiting the actual allowed range.</p>
  
  <p>Does this make a difference when it comes to indexes, query performance or any other aspect of the system?</p>