DAX Query Engine Internals
The VertiPaq engine, which is the core of
the new SQL Server Analysis Services Tabular engine, has an unprecedented level
of performance, thanks to its fine-tuned architecture and its ability to
perform fast cross-fltering. Automatic cross filtering between columns of the
same table or related tables is a very powerful feature of DAX. It allows a measure
to evaluate to different values for different cells in a pivot table even
though the DAX expression for the measure does not change. Filter context is
the underlying mechanism that enables this magic behavior. But it is also a
very tricky concept that even befuddles some DAX experts. In this session, we will
analyze the way DAX solves filtering. Starting from simple queries, we will
follow the steps DAX does with the filter context, discovering the internals of
the query engine of DAX.
Alberto Ferrari
Alberto Ferrari is a Business Intelligence consultant. Alberto helped several software houses to build complex BI solutions, from the OLTP to the final OLAP cubes, providing planning hints all over the development lifecycle. He is a book author also, having worked on "Exper Cube Development with Microsoft SQL Server 2008" with Marco Russo and Chris Webb and Microsoft PowerPivot for Excel 2010: Give Your Data Meaning with Marco Russo.
http://sqlblog.com/blogs/alberto_ferrari/default.aspx UID:SQLBITS1524SEQUENCE:0 DTSTAMP:20130526T030125Z END:VEVENT END:VCALENDAR