dbx/docs/content/docs/field-lineage.mdx

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---
title: Field Lineage
description: Trace where columns come from, how they are referenced, and which relationships may exist.
---
Field Lineage helps answer a common question: where does a column's data come from, and what might depend on it? Use it to understand complex schemas, inspect impact, and read legacy structures.
<Callout type="info">Field Lineage is enabled for MySQL, PostgreSQL, SQLite, SQL Server, Oracle, Redshift, DM, and GaussDB. Other engines may not expose enough relationship metadata for DBX to build useful lineage.</Callout>
## What It Helps With
- Before changing a column, see which tables, views, or queries may depend on it
- Understand relationships in an unfamiliar database
- Trace where report fields may originate
- Discover possible relationships that are not declared as foreign keys
## Relationship Sources
| Source | Confidence | Details |
| ----------------- | ------------- | ---------------------------------------------------------------------------- |
| Foreign keys | High | Constraints declared in the database |
| Views | High | Field mappings analyzed from view definitions |
| Query history | Medium | Relationships inferred from executed SQL, including `JOIN` and `WHERE` usage |
| Same-name columns | Low to medium | Possible relationships inferred from similar column names |
<Callout type="info">Field Lineage is an analysis aid, not a strongly governed lineage platform. For critical decisions, confirm results with database constraints, view definitions, and application code.</Callout>
## Navigation
- Search by table or column name
- Filter relationships by confidence
- Click a table or column to open data or structure views
- Start from one column and inspect upstream or downstream relationships
## Recommendations
- Treat foreign key and view relationships as the strongest signals
- Review query-history and same-name inferences carefully
- Before changing a column, combine lineage with schema diff and application code search
- For important business fields, add database constraints or documentation comments where possible
## Related Features
<Cards>
<Card title="Schema Browser" href="/en/docs/schema-browser">
Inspect tables, columns, foreign keys, and comments.
</Card>
<Card title="Schema Diff" href="/en/docs/schema-diff">
Compare structure differences across environments.
</Card>
</Cards>