> 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/add-sequence-step-article.md).

# Add sequence

The Add sequence step adds a sequence to the PDI stream. A sequence is an ever-changing integer value with a specific start and increment value. You can either use a database sequence to determine the value of the sequence, or have it generated by PDI. PDI-generated sequence values are unique when used in the same transformation, and return to the same starting value each time you run the transformation.

The following transformation steps may also be useful when working with sequences:

* [**Add value fields changing sequence**](https://wiki.pentaho.com/display/EAI/Add+value+fields+changing+sequence)

  Adds a sequence when the values of a field change. Each time a value of at least one field changes, the added sequence resets to its starting point.
* [**Group By**](/pdia-data-integration/9.3-data-integration/pdi-transformation-steps-reference-overview/group-by-landing-page-article.md)

  Builds aggregates by grouping and generates sequential numbers within rows with repeating values.

See the [Get ID from Slave Server](https://wiki.pentaho.com/display/EAI/Get+ID+from+Slave+Server) step if you need a unique ID in a clustered environment.


---

# 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/add-sequence-step-article.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.