title: How are OLAP-cube operations and MDX related?
body: <p>I would like to understand how OLAP-cube operations (i.e. drilling up/down, slicing/dicing and pivoting) and MDX are related.
  My current guess is that OLAP-cube operations to MDX are like relational algebra to SQL. However, I do not see how some basic features of MDX correspond to OLAP-cube operations. For example, consider the following query on the demo "Sales" cube that comes with icCube:</p>
  
  <pre><code>SELECT {([Ottawa],[2009]), ([United States],[Feb 2010])} on Rows,
         [Measures].members on Columns
  FROM [Sales]
  </code></pre>
  
  <p>How does the use of tuples (e.g. <code>([Ottawa],[2009])</code>) correspond to an OLAP-cube operation?</p>