In Tableau, a calculation returns different results depending on whether it is written as FIXED LOD vs a regular aggregate. What is the most likely cause?

Question

Tableau — Hard

In Tableau, a calculation returns different results depending on whether it is written as FIXED LOD vs a regular aggregate. What is the most likely cause?

Accepted Answer

FIXED LOD calculations yield different results due to their computation timing. They compute before most filters, except context filters. This timing discrepancy affects the data considered in the calculation. Regular aggregates, however, respect dimension filters.