title: Are user-defined SQL datatypes used much?
body: <p>My DBA told me to use a user-defined SQL datatype to represent addresses, and then use a single column of that new type in our users table instead of multiple address columns. I've never done this before and am wondering if this is a common approach.</p>
  
  <p>Also, what's the best place to get information about this - is it product-specific?</p>