The SUM aggregate function to compute the sum of the column or column expression with a numeric data type, specified by numeric_expression.
You cannot specify a SUM function in the definition of a column-partitioned join index.
The data type for any column defined by a SUM function must be typed as FLOAT to avoid numeric overflow.
If you do not assign a data type to a SUM column, the system types it as FLOAT automatically. If you assign a type other than FLOAT, the system returns an error to the requestor.
SUM DISTINCT is not permitted.
Each aggregate join index must be created with a COUNT(*) or a COUNT(value_expression ). If you do not specify this expression, the system adds a COUNT(*) to the definition to support index maintenance.
For more information about the SUM aggregate function, see SQL Functions, Expressions, and Predicates, B035-1145.