OBIEE EVALUATE Function

In the documentation for OBIEE 10.3.3.1 you find a very small description of the EVALUATE function:

6.1 EVALUATE Function
This function is intended for scalar and analytic
calculations.
Syntax: EVALUATE('DB_Function(%1)', {
Comma separated Expression})
Example: SELECT
e.lastname,sales.revenue,EVALUATE('dense_rank()
over(order by %1
)',sales.revenue) FROM sales s, employee e;

As often in practice the real world is more complex:
Good practice is to tell the EVALUATE function which type of return value it can expect:
EVALUATE('DB_Function(%1)' as returntype, {Comma separated Expression}). If you omit this it might sometimes complain that it can't concatenated values from a different type.

Another trap is when you use columns from several tables for the input variables, be sure that they have a direct join. Else OBIEE will try to join them underwater which can lead to unwanted Cartesian products.