dbt Lineage and Impact Analysis AI Prompt

Analyze data lineage and assess the impact of a proposed change in this dbt project.

Proposed change: {{change_description}} (e.g. rename column, change grain, drop a staging model)
Affected model: {{affected_model}}
Warehouse: {{warehouse}}

1. Understanding dbt lineage:
   dbt automatically builds a DAG (Directed Acyclic Graph) from all ref() and source() calls.
   Every model knows its parents (models it depends on) and children (models that depend on it).

2. Impact analysis commands:

   Find all downstream dependents:
   dbt ls --select fct_orders+   # all models downstream of fct_orders
   dbt ls --select +fct_orders   # all models upstream of fct_orders
   dbt ls --select +fct_orders+  # full lineage in both directions

   Identify exposed models (BI-facing):
   dbt ls --select fct_orders+ --resource-type exposure

   Check which metrics depend on a column:
   dbt ls --select metric:*      # list all defined metrics

3. Safe column rename process:
   Step 1: Add the new column with the new name alongside the old one
   Step 2: Deploy; validate downstream models use the new name
   Step 3: Remove the old column in the next deployment
   Never: rename a column and deploy in a single step without checking downstream

4. Breaking change checklist:
   Before merging any change to a widely-used mart model:
   ☐ Run: dbt ls --select {model}+ to list all downstream models
   ☐ Check: are any downstream models used in BI dashboards or exported to external systems?
   ☐ Notify: owners of affected downstream models
   ☐ Test: run full dbt build --select {model}+ in a dev schema
   ☐ Document: add a changelog entry to the model description

5. State-based CI (dbt Cloud / dbt Core):
   dbt build --select state:modified+
   - Only builds models that changed AND their downstream dependents
   - Dramatically faster CI than running the full project
   - Requires: dbt state artifacts from the last production run

Return: downstream impact list, safe change process, breaking change checklist, and state-based CI configuration.