This hotfix also applies to Microsoft SQL Server 2014 Analysis Services (SSAS 2014).
In Microsoft SQL Server 2012 Analysis Services (SSAS 2012) or SQL Server 2014 Analysis Services (SSAS 2014), the performance of an Multidimensional Expression (MDX) query may be much slower than the performance of the same query in early builds of SQL Server 2008 R2 Analysis Services (SSAS 2008 R2). This issue occurs if the query uses calculated members and Sub Select statement. Generally this kind of query is created by Excel.
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.