Drillthrough Performance with Dimension Attribute IsAggregatable =false

Environment: SQL2008R2 on Windows 2008 R2In our Testexample we have a cube with 3 Dimensions. 1 of them with about 4 mil rows. This is just for Drillthrough. The Fact Table has about 1.7 mil rows. Our dimension which causes the problem looks like this:Name: ZeitZeit_Jahr_Idx IsAggregatable=falseZeit_Tag_Idx(PK) IsAggregatable=trueThe Fact-Table has the Data on the Zeit_Jahr_Idx-Level.When I run a Drillthrough, which returns only Attributes of my Drillthrough Dimension, it takes about 1 minute and 40 seconds.If I change IsAggregatable=true on my Zeit_Jahr_Idx the query takes 1 second!!!!The Drillthrough looks like this:drillthrough select [Berichtsperiode].[Berichtsmonat].&[12] on 0 --Month from [VIS] where [Zeit].[Jahre].[Jahr].&[21]--Year return [$Bearbeitungen Detail].[VIS Bearbeitungen Detail Key Idx] as [Detail], [$Bearbeitungen Detail].[Branche] as[Branche]Can anyone explain why?? Thanx

Thanx, It seems that the problem is caused by the combination of IsAggregatable=false and that the Fact-Table is not related to Dimension on the Leaf-Level of the Dimension. If I have only a one-Level Hierarchydimension it works fine. But when I have a Multilevel-HierarchyDimension and the Fact-Table is related on a higher Level I'm getting poor performance

The installation of "SQL Server 2008 R2 Cumulative Update Package 6" solves this issue. Exactly: This Issue has been resolved by resolving another problem: FIX: The memory usage in SSAS 2008 or SSAS 2008 R2 may be larger than in SSAS 2005 when you create a local cubehttp://support.microsoft.com/kb/2422081