Using aggregate tables produce incorrect Year-to-date at the lowest levels.

Applies to:
Business Intelligence Server Enterprise Edition – Version: 7.9.5 [AA 1900] – Release: V7
Information in this document applies to any platform.
Symptoms
The user is modelling Time Series functionality (Todate) with aggregated dimensions and aggregated facts using BI Server 10.1.3.3.2.

You have created aggregate tables. You have both Logical Dimension and Fact tables mapped to the Aggregate tables.
In Answers you have built a report using the Dimension Hierarchy, which has the measures Sales and Sales YTD. When you drilldown in the report, the measures show the correct figures, until you get to the lowest level where the Sales YTD results are incorrect.
Cause

The cause of this incorrect aggregation when you drilldown to the lowest level of the hierarchy has been determined to be an incorrect sql being generated. The incorrect sql generated lacks the
SUM..GROUP BY

The main difference is that when you are at the lowest level of the aggregate table it doesn’t use “SUM..GROUP BY” in it’s core query.

The issue has been determined to be a Bug, as per Engineering who reviewed the issue.

Solution

However a workaround was provided for this specific customer scenario that resolved the issue. With the implementation below which engineering tested and verified the SUM and Group by was generated in the sql when drilling into the lowest level of the hierarchy.

”
I created a dimension that I just created in the business model and added the additional dimension to the content filter for the problem fact source. That resulted in SQL generation with a SUM clause. My workaround was used just for the problem query submitted. I did not even join the new dimension to the fact table.

So I would recommend creating a virtual dimension in the physical and business model layers. It should not be exposed in the presentation catalog.
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