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

# Column Lineage

> Trace column-level dependencies across SQL, dbt, and Spark.

## Overview

**Column lineage** traces how individual fields flow from source to sink - through SQL queries, dbt models, and Spark transformations. Use it to answer *which upstream column does this metric come from?* or *if I drop this column, what breaks?*

Column lineage is captured automatically when your producers emit OpenLineage with column-level facets. Most modern dbt and Spark integrations include this out of the box.