Group aggregate index rows on the AMPs. You cannot specify a GROUP BY clause in the definition of a column-partitioned join index. For a detailed description of the GROUP BY clause, see Teradata Vantage™ - SQL Data Manipulation Language, B035-1146.
- column_name
- The name of the column or columns within the join index definition select list used to group aggregate index rows on the AMPs. The GROUP BY column list must include all the non-aggregated columns for an aggregate join index.
- column_position
- The ordinal position of the column or columns within the join index definition select list used to group aggregate index rows on the AMPs. If you specify the system-derived ROWID column in the GROUP BY column list, it must have been previously aliased with a column name alias. You cannot specify the literal ROWID as part of the column list for the GROUP BY option of a join index definition. If you specify a GROUP BY clause, but do not specify a COUNT or SUM operator, the system adds a COUNT(*) expression, named CountStar, to the column list.
- column_alias
- An alias for the column or columns.
- expression_alias
- An alias for the expression.