> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview/merge-rows-diff/select-an-engine-merge-rows-diff/using-merge-rows-diff-on-pentaho-engine/options-reuse.md).

# Options

![Options for Merge rows (diff)](/files/Vobme2Vu9Z5sh24eCyaN)

The Merge rows (diff) step contains the following options.

| Option                    | Description                                                                                                                                                           |
| ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reference rows origin** | From the drop-down list, select the input source for the original reference rows you want to compare. The input source will be a previous step in the transformation. |
| **Compare rows origin**   | From the drop-down list, select the input source for the compare rows. The input source will be a previous step in the transformation.                                |
| **Flag fieldname**        | Specify a field name that will contain the flag indicating how the values were compared and merged in the output row.                                                 |
| **Keys to match**         | Specify the field names that contain the keys on which to generate a match.                                                                                           |
| **Values to compare**     | Specify the field names that contain the values on which to generate a comparison.                                                                                    |
| **Get key fields**        | Click the **Get key fields** button to populate the **Keys to match** table with all the fields in the **Reference rows origin** step.                                |
| **Get value fields**      | Click the **Get value fields** button to populate the **Values to compare** table with all the fields in the **Compare rows origin** step.                            |


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.pentaho.com/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview/merge-rows-diff/select-an-engine-merge-rows-diff/using-merge-rows-diff-on-pentaho-engine/options-reuse.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.