5 Replies Latest reply on Apr 13, 2013 4:03 PM by Syed Shah

    OLAP Limitations / Differences?

    Robin Sarac

      Has anyone found a clear outline of how Tableau behaves differently when connected to an OLAP cube instead of a regular table?  One of our users connects to cubes routinely and I'm often at a loss because the experience is quite different.

        • 1. Re: OLAP Limitations / Differences?
          Ed Egan

          We use Tableau exclusively against our OLAP database.  I know of no clear outline that documents the differences, it's just been a learning curve.  A big difference is that you cannot make calculations against dimensions directly you have to build calculated measures.    I found that data sets and calculations are best created in the cube itself as opposed to within Tableau.  Is there anything specific you are trying to accomplish?

          • 2. Re: OLAP Limitations / Differences?
            Robin Sarac

            Thank you very much for responding with your experience!

             

            I'm not trying to accomplish anything specific at this point.  To be honest, I was just surprised at how different it was.  I guess, when I think of it, I shouldn't be surprised that the experience would be different considering how OLAP works.

             

            We're running a pilot in our organization that has us testing Tableau Server and considering a much wider deployment of Tableau Professional.  Understanding how different the experience is when connected to OLAP cubes is important because, frankly, it change Tableau's promise a bit.  Also, it may cause us to reconsider when a cube makes sense.  IF the flexibility isn't there and there isn't enough data that pre-aggregated data delivers a huge boost in performance...

             

            I had trouble throwing in a Number of Records calculated measure which is normally available by default.  It seemed to return 1.  This isn't surprising as Analysis Services was probably legitimately returning one row served from a pre-aggregated slice in the cube.

            • 4. Re: OLAP Limitations / Differences?
              guest contributor

              Thank you for the link!  That's very helpful indeed.

              • 5. Re: OLAP Limitations / Differences?
                Syed Shah

                Hi Ed,

                 

                I have a few questions regarding olap cube usage in tableau

                1. How to use parameter in MDX expression as we cannot use dimensions in calculated field
                2. How to create relative week filter. I want a filter which select last 13 weeks by default
                3. I am trying to create a scatter plot. However I don’t know how to disaggregate the measures when using cube

                Can you please provide some help or guidance here

                 

                Syed