title: Storing money in a decimal column - what precision and scale?
body: <p>I'm using a decimal column to store money values on a database, and today I was wondering what precision and scale to use.</p>
  
  <p>Since supposedly char columns of a fixed width are more efficient, I was thinking the same could be true for decimal columns. Is it?</p>
  
  <p>And what precision and scale should I use? I was thinking precision 24/8. Is that overkill, not enough or ok?</p>
  
  <hr>
  
  <p>This is what I've decided to do:</p>
  
  <ul>
  <li>Store the conversion rates (when applicable) in the transaction table itself, as a float</li>
  <li>Store the currency in the account table</li>
  <li>The transaction amount will be a <code>DECIMAL(19,4)</code></li>
  <li>All calculations using a conversion rate will be handled by my application so I keep control of rounding issues</li>
  </ul>
  
  <p>I don't think a float for the conversion rate is an issue, since it's mostly for reference, and I'll be casting it to a decimal anyway.</p>
  
  <p>Thank you all for your valuable input.</p>