Last week was a very interesting week at the PASS conference in Seattle.  Microsoft made a lot of announcements about "Denali", the next version of SQL Server.  For myself, the most interesting announcements were that the Vertipaq technology that Microsoft has developed would be embedded into SQL Server itself and that Microsoft Analysis Services would be extended with a new BI Semantic Model (BISM).  Two people that I respect greatly, T.K. Anand and Chris Webb have both written extensively about these topics in their blogs.

T.K. comments: "There will always be sophisticated BI applications that need the power of MDX calculations and we envision that the BI Semantic Model will offer the choice of MDX as well, but this will likely come in a release after Denali."

Chris comments: "BISM models will also be able to operate in ‘passthrough’ mode. This is essentially ROLAP done right, and a lot of work has gone on around this; in Denali it will only be available for SQL Server and only if you’re issuing DAX queries, not MDX. In the future other RDBMSs will be supported, plus possibly MDX querying of BISM when it’s in passthrough mode. Essentially in this scenario when you query the model your query is translated direct to SQL, and the results returned are (as far as possible) passed back to you directly with the minimum of interference. In some cases, for example where there are calculations, BISM will do some stuff with the resultset before it hands it over to you, but the aim is to push as much of the logic into the SQL query that it generates. If it works well, it sounds like at long last we’ll have a serious ‘realtime’ BI option, though I’m still not sure how well it will perform; I suppose if there are Vertipaq indexes inside SQL Server and/or if you’re using PDW, the performance should be good."

There was a lot of confusion last week and to fully understand the directions on Analysis Services and the MDX query language, I very strongly recommend you read the following:

1. Analysis Services – Roadmap for SQL Server “Denali” and Beyond:

2. PASS Summit 2010 Day 1:

3. PASS Summit Day 2:

4. PASS Summit Day 2: The Aftermath:

After you read all of this and digest it, I would love to hear any comments you have.  Also, keep in mind that Microsoft just released the first CTP of SQL Server "Denali" and none of the Analysis Services features are in this CTP.  Therefore, we need to wait for the next CTP to start playing with any of this and my expectation is that "Denali" will not likely be available until mid to late 2011.