In the Fields area of the Joiner, you can perform the following tasks:
Remove fields from the join
Add aliases to duplicate field names
Removing fields from the join
You can remove unnecessary fields from the join. Just uncheck the box next to any field you don’t want to include in the join, and then click Get Schema to refresh the Output Schema. All unchecked fields will be dropped when you run the pipeline.
However, if your datasets are very large, removing fields in the Joiner can have a performance impact. For more information, see Optimizing Joiner performance.
Adding aliases to duplicate field names
Field names in the output schema must be unique. If the input schemas have field names that are identical, you can either use the Wrangler to rename the fields or add aliases in the Joiner.
After you add aliases, click Get Schema to refresh the Output Schema.