> For the complete documentation index, see [llms.txt](https://documentation.astera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.astera.com/astera-data-stack-v9/data-model/data-models/introducing-data-models.md).

# Introducing Data Models

A data model is a logical structure that incorporates the various tables present within a database, and the relationships between them. In essence, it outlines the connections present between the datasets existing in a particular database, thus illustrating how these datasets are stored and processed within the system.

Astera Data Stack allows its users to create a data model from scratch using the entities available in the toolbox, or to generate a data model for an already existing database using the reverse engineer option. Moreover, you can also create and edit entity relationships, modify entity layouts, and add and modify indexes using this functionality.

Here is a sample data model that has been reverse engineered from an existing database.

![](/files/La1PEuU0n4MhiyboZMnd)

The boxes represent the tables present in the database and the lines connecting these boxes are an indicator of the relationships between these tables.


---

# 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:

```
GET https://documentation.astera.com/astera-data-stack-v9/data-model/data-models/introducing-data-models.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.