In the opening keynote and again in his sessions, Christian demonstrated Power BI reports on the taxi driver activity database with over a trillion rows of raw data. The larger dataset was in a Spark cluster, accessed using DirectQuery. Aggregated tables were stored in the in-memory model using the new composite model feature. As the data was explored in report visuals, the Power BI engine would seamlessly switch from tabular in-memory aggregate tables to DirectQuery source data in order to return low-level details. Composite models will allow mashing-up imported database and file-based data with an DirectQuery.
There are limits and complexities with these new features. You cannot mashup imported tables in a Power BI model based in a direct connection to SSAS, but enterprise-scale features in Power BI arguably may not steer a solution architect to select SSAS over Power BI for serious data modeling. With incremental data refresh, large model support, row-level security and many other “big kid” features, Power BI might be a preferable choice. I’m not ready to rule-out Analysis Services as the better option for most enterprise solutions – at least not in the near future, but Power BI is definitely heading in that direction.
Click through for several other features which help convince Paul that Power BI is threatening Analysis Services for enterprise data analysis solutions.