Last week the final session evaluations from PASS Summit 2011 have been communicated to speakers and best scores have been made public. My session was not particularly good: it had very good feedback (overall average 4.32) and some average one, mostly because the title (Vertipaq vs OLAP: Change Your Data Modeling Approach) suggested to someone a comparison about MOLAP and Vertipaq engines, whereas I dedicated the session to differences in data modeling for those two models. I know, I have to compare the two engines and I will do in the future, but only after some real data is gathered in real projects. It is not just a question of performance, but also of scalability and resources requested in order to run a system.

But the reason for the blog post is that the best session in the BI Platform Architecture, Development and Administration track has been the Many-to-Many Relationships in DAX by Alberto Ferrari, which achieved an outstanding overall average score of 4.84 and is the 5th session in overall ranking of PASS Summit 2011, tied with Peter Myers session (which is also the top in BI Information Delivery – PowerPivot and DAX rocks this year). If you attended PASS Summit you should be able to view the streamed recording of the session. In any case, you can download for free the white paper The Many-to-Many Revolution 2.0, which contains the whole content of Alberto’s session, plus more models and corresponding techniques in Multidimensional models. I and Alberto worked on this paper in the months before PASS Summit and we expect to review the paper in late 2012, after we’ll have shipped the upcoming book we are writing with Chris Webb. This is the reason we have released few new articles in the last months, but soon we will start writing more articles, stay tuned!

I always try to understand from session feedback what can be improved in my delivery and what are the reasons a session is appreciated by the attendees. To my, the goal of attending a session is to learn something and looking to a topic from a different perspective. Votes and comments, in session, evaluations are not the ultimate judgment, but they are helpful in understanding the attendee’s perception. Alberto’s session on Many-to-Many relationship is very well prepared and has a very good animated graphical representation of calculations going on behind the scenes. This is very expensive in preparing the session (every animated slide may require one hour or more, and there are many!), but it is clearly a very good way to communicate effectively. Well, more lessons learned that I think will be helpful next year, many conferences are coming.