17.10 - Nesting Aggregates - Advanced SQL Engine - Teradata Database

Aggregate operations cannot be nested. The following aggregate is not valid and returns an error:

   AVG(MAXIMUM (Salary)) 

Although direct nesting of aggregates is not supported, nested aggregates can be evaluated using a derived table that contains the aggregates to be nested. For more information, see Teradata Vantage™ - Time Series Tables and Operations, B035-1208.

Also, aggregates can be nested in aggregate window functions. The following statement is valid and includes an aggregate SUM function nested in a RANK window function:

   SELECT region
      ,product
      ,SUM(amount) 
      ,RANK() OVER (PARTITION BY region ORDER by SUM (amount))
   FROM table;