> ## Documentation Index
> Fetch the complete documentation index at: https://docs.paradime.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Compare column-level lineage on pull requests

> Surface the exact downstream columns and dashboards affected by a dbt™ pull request, so reviewers can approve changes with confidence.

Column-Level Lineage Diff shows the blast radius of a pull request directly in the PR. It identifies structural column changes in your dbt™ models and posts an automated comment listing every impacted downstream node, so reviewers see exactly what's affected before they merge.

<Note>
  **Prerequisites**

  * A connected [git provider](/products/bolt/ci-cd/lineage-diff/index) so Paradime can post PR comments.
  * A [production connection](/products/settings/connections/scheduler-environment/index) with access to your sources and models, so Paradime can run information schema queries and build field-level lineage.
  * At least one [Turbo CI schedule](/guides/orchestrate-data-pipelines/set-up-turbo-ci) configured, which is required to generate field-level lineage.

  Estimated time: 15 minutes.
</Note>

## Steps

<Steps>
  <Step title="Confirm your production connection and Turbo CI">
    Make sure your production connection is in place and at least one Bolt Turbo CI schedule runs successfully. Together they let Paradime build the field-level lineage the diff relies on.
  </Step>

  <Step title="Connect your git provider">
    Connect the git provider that hosts your dbt™ repository so Paradime can read pull requests and post comments back. Follow the reference page for your provider in the section below.
  </Step>

  <Step title="Connect your BI tools">
    Connect BI tools like [Looker](/products/bolt/ci-cd/lineage-diff/index), Tableau, or ThoughtSpot so the report also surfaces affected dashboards and other downstream assets, not only dbt™ models.

    <Info>
      Connecting BI tools gives you the widest impact coverage, so reviewers see the full downstream picture.
    </Info>
  </Step>

  <Step title="Open a pull request with a column change">
    Open a test PR that renames, removes, or adds a column in a SELECT statement, for example renaming `customer_name` to `full_name`. These structural SELECT changes are what the diff detects.

    ```sql theme={"system"}
    -- Before
    SELECT
        customer_id,
        customer_name,
        email
    FROM customers

    -- After (column renamed)
    SELECT
        customer_id,
        full_name,
        email
    FROM customers
    ```

    <Info>
      The diff tracks structural changes to SELECT statements (column renames, removals, and additions). It does not track logic changes in `WHERE`, `JOIN`, `GROUP BY`, or `ORDER BY` clauses, or changes to how a column value is calculated.
    </Info>
  </Step>

  <Step title="Review the impact report">
    Paradime posts an automated comment on the PR listing all impacted downstream dbt™ models and BI nodes. Use it to assess the potential impact of the change before approving.
  </Step>
</Steps>

<Check>
  You'll know it worked when your test PR receives an automated comment listing the affected downstream nodes. If the comment reports it can't find your public git email address, complete the git provider setup for the user opening the PR on the provider reference page.
</Check>

## Set up your git provider

Finish the connection on the reference page for your provider. BI integrations for Looker, Tableau, and ThoughtSpot are covered from the same section.

<CardGroup cols={2}>
  <Card title="GitHub" href="/products/bolt/ci-cd/lineage-diff/github" horizontal />

  <Card title="GitLab" href="/products/bolt/ci-cd/lineage-diff/gitlab" horizontal />

  <Card title="Azure DevOps" href="/products/bolt/ci-cd/lineage-diff/azure-devops" horizontal />

  <Card title="BitBucket" href="/products/bolt/ci-cd/lineage-diff/bitbucket" horizontal />
</CardGroup>

## Next steps

<CardGroup cols={2}>
  <Card title="Set up Turbo CI" href="/guides/orchestrate-data-pipelines/set-up-turbo-ci" icon="git-branch">
    Run and test dbt™ changes on every pull request.
  </Card>

  <Card title="Lineage Diff reference" href="/products/bolt/ci-cd/lineage-diff/index" icon="search">
    Supported changes, BI integrations, and setup details.
  </Card>
</CardGroup>


## Related topics

- [Column Level Lineage](/products/dino-ai/tools-and-features/column-level-lineage.md)
- [Column-Level Lineage Diff](/products/bolt/ci-cd/lineage-diff/index.md)
- [Column-Level Lineage Diff for Looker](/products/bolt/ci-cd/lineage-diff/looker.md)
- [Column-Level Lineage Diff on BitBucket](/products/bolt/ci-cd/lineage-diff/bitbucket.md)
- [Column-Level Lineage Diff on Azure DevOps](/products/bolt/ci-cd/lineage-diff/azure-devops.md)