UPDATE 2017-07-12: please note this article was written in 2010, there are now better ways to obtain the same result. Please read these articles: Physical and Virtual Relationships in DAX and Propagate filters using TREATAS in DAX PowerPivot supports  Read more

A calculated column is a DAX expression which is evaluated when the PowerPivot workbook is updated. It is very useful, but there are cases where you want to delay calculation at query time. For example: You want to make part of the calculation depending  Read more

PowerPivot for Excel is an Add-In which uses a local version of Analysis Services (SSAS) to process data and make calculation to respond to user queries made using Excel 2010. The SSAS engine is loaded in-memory in the process of Excel. Especially with  Read more

The calculation for ABC analysis can be made in PowerPivot using calculated columns. In this way each row can have an attribute with the appropriate ABC class. The ABC calculation has to be made considering a particular grouping and sort order. For example,  Read more

The CALCULATE function in DAX is the magic key for many calculations we can do in DAX. However, it is not pretty intuitive how it works and I spent a lot of time trying to understand how it can be used. First of all, this is the syntax. CALCULATE( <expression>,  Read more

UPDATE: PowerPivot for Excel 2010 in SQL Server 2012 and Excel 2013 support the DISTINCTCOUNT aggregation in DAX. This blog post is relevant only if you use PowerPivot for Excel 2010 in SQL Server 2008 R2. A PivotTable based on PowerPivot data doesn’t  Read more

UPDATE: This blog post is still good for learning DAX principles, but a better description of many-to-many patterns is available on The Many-to-Many Revolution whitepaper that is available here: http://www.sqlbi.com/articles/many2many/ – please download  Read more