After you have created your join, you can modify it through the Script PanelRecipe panel. When you click the script recipe step in the panel, the join is loaded into the Join page, where you may edit your join's datasets, keys, included columns, and join type before adding it back to the scriptrecipe.
NOTE: If you modify the selected dataset to join, the snapshot to use of the joined dataset, the join keys, or the fields to include in the output, subsequent steps in your transform script recipe can be broken by the change. After you modify the join, you should select the last step in your script recipe to validate all steps in the subsequent stepsrecipe.
For more information on creating or modifying joins, see Join Page.
Tip: From the Script PanelRecipe panel, you can click the Undo button to revert the last edit to your join step.
For more information, see Script Recipe Panel.