title: Time and date dimension in data warehouse
body: <p>I'm building a data warehouse. Each fact has it's <code>timestamp</code>. I need to create reports by day, month, quarter but by hours too. Looking at the examples I see that dates tend to be saved in dimension tables. <a href="https://i.stack.imgur.com/octOP.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/octOP.jpg" alt="alt starexample"></a><br>
  <sub>(source: <a href="http://etl-tools.info/images/dw_star_schema.jpg" rel="noreferrer">etl-tools.info</a>)</sub>  </p>
  
  <p>But I think, that it makes no sense for time. The dimension table would grow and grow. On the other hand JOIN with date dimension table is more efficient than using date/time functions in <code>SQL</code>. </p>
  
  <p>What are your opinions/solutions ?</p>
  
  <p>(I'm using Infobright)</p>