title: When to create a new table?
body: <p>I have an application with employees and their work contracts.
  Each work contract has a Vacation. We keep track of how many days the company owes the employee ("VacationOwe") and how many he has taken ("VacationTaken").</p>
  
  <p>Should I make this "VacationOwe" and "VacationTaken" a property of the Contract, or should I create a class (table) called Vacaction with the properties "VacationOwe", "VacationTaken" and "ContractId" and join the two tables?</p>
  
  <p>What are the advantange of both methods?<br />
  Is there any rule when you should create a new class or table or keep the data in one.</p>