Aggregation performs a selected calculation on a set of values and returns a single group value.
If grouping by a tuple type field, the only supported aggregation method is count.
Using the aggregation function in a Flow may cause the additional partitions resulting in multiple output files.
- Enter a name for the step.
- Select an argument to group by. This creates groups from identical data values in a selected field.
- Additional arguments can be added by clicking the Add Group by button.
- Select an aggregation method.
- Concat - Returns a string of the concatenated values in a group.
- Count - Returns the count of the number of field values of a group.
- First - Returns the first value in the field from the group.
- Last - Returns the last value in the field from the group.
- List - Returns a list of the concatenated values in a group.
- Sum - Returns the sum value of a field in a group.
- Fill in the configuration fields for the selected aggregation method.
- Additional aggregations can be added by clicking the Add Aggregation button.
- Click OK.
Nested fields are supported for both the group by and aggregation features of this function.