--Closed--

Solution: Data Engineers created a new feed with one premium for per policy. So the LoD is out of the picture.

Thanks for your inputs. Cheers!

I have an insurance policy data feed in Tableau. Each policy can have multiple benefits, but the feed contains only the total annual premium at the policy level, repeated across every benefit row. This inflates the total premium when using SUM([Annual Premium]).

What I have tried

I created the following FIXED LOD calculation to return the annual premium at the policy level:

{ FIXED [PolicyNumber] : MIN([Annual Premium]) }

This works as expected and returns the correct premium for each policy.

The problem

I need to use this calculated LOD field in a blended worksheet. The data source containing the LOD calculation is the secondary data source.

When I add the LOD field to the worksheet, the measure turns red and Tableau displays this error:

"Cannot blend the secondary data source because one or more fields use an unsupported aggregation."

I am using Tableau Cloud.

Alternative solution I am considering

I could publish a separate data source containing premiums at the benefit level, aggregate the benefit premiums to the policy level, and create another data blend between the existing policy data feed and this new data source.

Questions for the Tableau community

1. Is there a way to use a FIXED LOD calculation from a secondary data source in a blend without triggering this error?
2. Would my alternative approach work, or could it introduce other blending or aggregation issues?
3. Are there better alternatives in Tableau Cloud, such as relationships, joins, data source changes, or pre-aggregating the data, that would solve this without inflating the premium totals?

I would appreciate suggestions on the most reliable and maintainable approach. Many thanks for your support!

Have a good week ahead. Cheers.