For built-in ordered analytic functions specific to Teradata Database, such as CSUM and MAVG, GROUP BY determines the partitions over which the function executes. For an example, see Example: Specifying GROUP BY Using an Ordered Analytic Function.
For window functions, such as SUM and AVG, GROUP BY collapses all rows with the same value for the group-by columns into a single row. The GROUP BY clause must include all the columns specified in the:
- Select list of the SELECT clause
- Window functions in the select list of a SELECT clause
- Window functions in the search condition of a QUALIFY clause
- The condition in a RESET WHEN clause
For examples and more information on GROUP BY and ordered analytical functions, see Teradata Vantage™ SQL Functions, Expressions, and Predicates, B035-1145.