Aggregate-Step Icons

Teradata Visual Explain User Guide

Teradata Tools and Utilities
Visual Explain
User Guide
Aggregate-Step Icons 
Icon Function Description
Sampling An aggregate step that performs the sampling of data.
Statistics An aggregate step that operates on grouped rows and computes a new function value for the row given the function specification. This is similar to aggregates in that it operates on grouped rows and a filtering QUALIFY clause analogous to the HAVING clause. It is different from aggregates because it returns a value for each participating row (unless filtered out), and it allows other descriptive columns that are not in the group-by list to be specified in the SELECT list.
Sum An aggregate operator that returns a column value. The value is the arithmetic sum for a specified expression for a group. An expression is a constant or column expression for which the sum value is computed and that cannot contain any ordered analytic or aggregate functions.