'Unknown function sum called' error when trying to create a calculated field in tableau

1
votes

I'm connecting to a SSAS data source from Tableau, and I'm having the following problem:

When I tried to create a calculated field in tableau, it gave me the "Unknown function sum called" error. I was doing a calculation as simple as this:

sum([Test Score])/sum([Score Count])

When using an Excel connection, the sum function works just fine. Is this some limitation of working with SSAS from Tableau?

Thanks ahead for any help!

1
ssastableau-api

1 Answers

5
votes

When connected to a cube, aggregation functions such as SUM(), AVG() and similar are not available in the Tableau calculation editor [...] the aggregations have already occurred in the cube, and cannot be further aggregated. Note that you can also use Tableau Table Calculations to perform post-OLAP aggregation operations on the cell-level results from the cube.