[nQSError: 42015] Cannot function ship the following expression: Evaluate

Evaluate can be used to call db functions in OBIEE. However some times when we call the db function in OBIEE Analytics, it throws the below mentioned error.

This error comes from the fact that OBI is unable to know which aggregation rule it must apply when you ask for a total in a view. You have to define the answer aggregation rule in the column formula of in the view to resolve this error. 

Solution
Specify the Aggregation rule for the column in the edit formula of column in Analysis.