title: Horizontal Database and Vertical Database
body: <p>I am working on a social networking site with a family tree that is GEDCOM-compliant. We need to decide if we should use a horizontal or vertical database structure for User profiles. So, I would like to know if anybody can answer when to use a horizontal database structure and when to use vertical database structure.</p>
  
  <p>I found some answers for shopping sites where fields are not decided: a vertical database structure should be used. But I am confused about what to use for a family tree site. Should I use vertical or horizontal?</p>