[FAQ] Difference Between ref() and source() in dbt

[kkh1902]

Course

data-engineering-zoomcamp

Question

What is the difference between ref() and source() in dbt?

Answer

In dbt, source() and ref() are both used to reference tables, but they serve different purposes in the data pipeline.

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source() – Referencing External Source Tables

source() is used to reference raw or external tables that are not created by dbt.
These tables usually live in a data warehouse such as BigQuery or Snowflake and are defined in a sources.yml file.

Key points:

• Used for raw / upstream data

• Defined in sources.yml

• dbt does not control how the table is created

• Enables freshness checks, documentation, and testing

Example:

SELECT *
FROM {{ source('raw', 'trips') }}

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ref() – Referencing dbt Models

ref() is used to reference other dbt models (SQL files inside the dbt project).
dbt uses ref() to automatically manage model dependencies and execution order.

Key points:

• Used for dbt-generated models

• Automatically resolves schema and table names

• Controls run order and lineage

• Enables DAG, documentation, and refactoring safety

Example:

SELECT *
FROM {{ ref('stg_trips') }}
Checklist

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[github-actions]

✅ FAQ NEW proposal created in PR #85

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