Memory Group by
PLEASE NOTE: This documentation applies to an earlier version. For the most recent documentation, visit the Pentaho Enterprise Edition documentation site.
Description
This step builds aggregates in a group by fashion and does not require a sorted input since it processes all rows within memory. When the number of rows is too large to fit into memory, you need to use the combination of the Sort rows and Group by steps.
Options
Option | Definition |
|---|---|
Step name | The name of this step as it appears in the transformation workspace. |
Always give back a result row | If you enable this option, the Group By step will always give back a result row, even if there is no input row. |
The field that make up the group | After retrieving fields using the Get Fields button, designate the fields to include in the group. See the Group be step for more details. |
Aggregates | After retrieving fields using the Get lookup fields button, designate the fields to include in the group. See the Group be step for more details. |
Metadata Injection Support (7.x and later)
All fields of this step support metadata injection. You can use this step with ETL Metadata Injection to pass metadata to your transformation at runtime.