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SSAS - Test Aggregations No aggregations are hit

Jan 29, 2016 at 11:37 AM

I've been having an issue lately regarding the Test Aggregation Performance feature.

Yesterday morning I ran the test on a partition and in the final report, all aggregations were sucessfully hit (Hit Agg column = True). However, in the afternoon, I ran the test again after editing some aggregations using BIDS helper, and then all the sudden all tests I made, even on other partitions, ended up telling that no aggregation is hit ( Hit Agg column = False).

I rebuilt the cube (full process), and I also tried deleting the aggregations and creating new ones using the wizard and also a single basic Aggregation to try to debug this, but I never got any hit, and all I got was "False" in the hit agg column.

Is this some sort of bug in BIDS Helper?
Jan 29, 2016 at 12:04 PM
Here is sample Test report I've just ran now. I created 2 aggregations and these queries don't hit them. Can't undertand why... Running theses queries that BIDS helper generates, in SSMS, it returns no data, and in Profiler there are no "get data from aggregations" or "get data from partition" events...

Jan 29, 2016 at 12:33 PM
Edited Jan 29, 2016 at 12:33 PM
Well, I accidentally found out why this happens. It's all a visibility issue.

The queries that BIDS helper generates for the test use the function MeasureGroupMeasures(). And I was testing the query for a given measure group and I found it strange that it gave me no results. I investigated a little and found that this function only returns Measures and not Calculations. Since I have the measures in this measure group hidded (visibility = false), this query never produces any results.

All I had to do is set the measure group measures visibility to true, and the test ran successfully. :)

I believe it might be worth a change in the query that BIDS helper generates. Instead of just referencing the Measures, it could also call all calculations as well with this MDX:
Instead of
This way, even if the Measures are all hidden, the tests run as expected, since they will test query performance for every calculated member.
Marked as answer by fjlour on 1/29/2016 at 4:38 AM