> ## 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.
# Column-Level Lineage Diff
> Column-Level Lineage Diff shows the exact upstream and downstream columns impacted by a dbt™ pull request, so reviewers can approve changes confidently.
export const Arcade = ({src, title}) =>
;
**Overview**
The Column-Level Lineage Diff Analysis feature in Paradime enables users to understand the blast radius of their changes directly within pull requests (PRs). By leveraging field-level lineage, this CI check identifies changes to columns in your dbt™ models and creates a report for all impacted downstream objects. This includes renaming or removing columns and changes to the underlying logic of columns in your dbt™ models.
When a PR is opened in GitHub, an automated comment is generated listing all downstream nodes. This allows users to understand the changes introduced at a column level and assess the potential impact on downstream dbt™ models, BI dashboards, and other downstream elements.
## Key features
* **Field-Level Lineage**: Identify changes to columns in your dbt™ models and generate a detailed report of all impacted downstream objects.
* **Automated Comments**: Receive automated comments in your PRs listing all downstream dbt™ models and BI nodes affected by the changes.
* **Impact Assessment**: Understand what nodes and other elements might be impacted by the changes introduced in the PR.
## Use cases
* Assess all downstream nodes impacted by changes both within a dbt project and in downstream application (example: BI)
* For Data Mesh architectures, see how your current project's changes impact other project changes.
## Tutorial
## Prerequisites
To use the Column-Level Lineage Diff Analysis features, ensure the following prerequisites are met:
1. **Git Integration**: Install the Paradime GitHub app and authorize access to the dbt™ repository used in Paradime or use alternative methods based on your Git Provider. See setup instructions.
2. **Production Connection**: Add a production connection with access to your sources and models generated when running production jobs. This allows Paradime to run information schema queries and build field-level lineage. See [connection guide](/products/settings/connections/scheduler-environment/index) for instructions based on your data warehouse provider.
3. **Have at least one Bolt TurboCI configured**. This is required to generate field-level lineage for your dbt™ project. See [Bolt Scheduler](/products/bolt/creating-schedules/deploy) for configuration.
To get the most value out of Lineage Diff Analysis, connect your BI tools ([Tableau](/integrations/tableau), [Thoughtspot](/integrations/thoughtspot), [Looker](/integrations/looker), etc.) to see all downstream nodes impacted.
## Set up your Git provider
## Lineage Diff Feature - Supported Use Cases
The lineage diff feature analyzes changes in dbt models to track structural modifications that affect downstream dependencies.
The lineage diff feature focuses on **structural changes to SELECT statements** that affect the schema and column availability for downstream models. It does not track logic changes, data transformations, or modifications to non-SELECT clauses.
**Supported Changes**
**SQL Structural Changes**
The lineage diff feature detects and tracks the following structural modifications:
* **Column renaming**: When a column is renamed in a SELECT statement
* **Column removal**: When a column is removed from a SELECT statement
* **Column addition**: When a new column is added to a SELECT statement
**Example - Supported Changes**
```sql theme={"system"}
-- Before
SELECT
customer_id,
customer_name,
email
FROM customers
-- After (column renamed)
SELECT
customer_id,
full_name, -- renamed from customer_name
email
FROM customers
```
**Non-Supported Changes**
**Structural Changes to Non-SELECT Statements**
* **WHERE clause modifications**: Changes to filtering conditions
* **JOIN modifications**: Adding, removing, or changing JOIN conditions
* **GROUP BY changes**: Modifications to grouping logic
* **ORDER BY changes**: Changes to sorting logic
**Structural Changes Used in Non-SELECT Contexts**
Even if a change is structural (like renaming a column), the lineage diff feature does not track usage in:
* **WHERE clauses**: Column references in filtering conditions
* **JOIN conditions**: Column references in table joins
* **GROUP BY clauses**: Column references in grouping logic
* **ORDER BY clauses**: Column references in sorting logic
**Data Changes**
* **Column calculation changes**: Modifications to how a column value is computed
* **NULL handling changes**: Changes in NULL value treatment
* **Data type transformations**: Changes that affect data representation but not structure
**Example - Non-Supported Changes**
```sql theme={"system"}
-- Before
SELECT
customer_id,
customer_name,
revenue * 1.1 as adjusted_revenue
FROM customers
WHERE status = 'active'
ORDER BY customer_name
-- After (non-supported changes)
SELECT
customer_id,
customer_name,
revenue * 1.2 as adjusted_revenue -- calculation change (not detected)
FROM customers
WHERE status IN ('active', 'pending') -- WHERE clause change (not detected)
ORDER BY full_name -- ORDER BY with renamed column (not detected)
```
**Note**: Even though `customer_name` was structurally renamed to `full_name`, the lineage diff feature only tracks this change in the SELECT statement itself, not its usage in the ORDER BY clause.
## Summary
Column-Level Lineage Diff helps you review downstream impact before merge. It detects structural column changes in `SELECT` statements, then reports affected dbt™ models and connected BI assets in your PR.
It is best for column additions, removals, and renames. It does not track logic changes in `WHERE`, `JOIN`, `GROUP BY`, `ORDER BY`, or column calculations.
## Next steps
1. Connect your Git provider so Paradime can post PR comments.
2. Add a production connection and confirm at least one Bolt schedule runs.
3. Connect BI tools like Looker, Tableau, or ThoughtSpot for wider impact coverage.
4. Open a test PR with a column change and review the generated lineage report.
## Related topics
- [Lineage Diff](/developers/python-sdk/modules/lineage-diff.md)
- [Column-Level Lineage Diff for Looker](/products/bolt/ci-cd/lineage-diff/looker.md)
- [Column-Level Lineage Diff on GitHub](/products/bolt/ci-cd/lineage-diff/github.md)
- [Column-Level Lineage Diff on GitLab](/products/bolt/ci-cd/lineage-diff/gitlab.md)
- [Column-Level Lineage Diff on BitBucket](/products/bolt/ci-cd/lineage-diff/bitbucket.md)