Retains rows with distinct values
The step calculates group fields for each row, and only passes distinct combinations of group fields through the out gate. It discards all rows with previously seen group fields.
Defines the grouping of rows.
Evaluated for each input row
- Data type of the grouping field. Values are implicitly cast to this type.
- Name of the grouping field.
- Value of the grouping field.
This step can optimize row output and memory consumption if it is guaranteed that incoming rows are sorted by group fields.
Evaluated once when step initializes
|dict||Current grouping variables.|