source() function for raw tables in dbt - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the source() function in dbt?

The source() function in dbt is used to reference raw tables or external data sources in your project. It helps you track and document where your data comes from.

beginner

How do you use the source() function in a dbt model?

You use source('source_name', 'table_name') inside your SQL to refer to a raw table defined in your sources.yml file. This makes your code clear and maintainable.

beginner

What file do you configure to define sources for the source() function?

You define sources in a sources.yml file inside your dbt project. This file lists the source names and their raw tables with metadata.

intermediate

Why is using source() better than hardcoding raw table names?

Using source() helps track data lineage, improves documentation, and makes your project easier to update if raw table names or locations change.

intermediate

Can source() be used to reference tables outside your dbt project?

Yes, source() can reference external raw tables as long as they are defined in your sources.yml file and accessible by your data warehouse.

What does source('raw', 'customers') do in dbt?

A References the 'customers' table from the 'raw' source defined in sources.yml

B Creates a new table called 'customers' in the 'raw' schema

C Deletes the 'customers' table from the 'raw' source

D Runs a transformation on the 'customers' table

The source() function references an existing raw table defined in sources.yml. It does not create, delete, or transform tables.

Where do you define the sources used by the source() function?

A In the <code>models/</code> folder

B In the <code>sources.yml</code> file

C In the <code>dbt_project.yml</code> file

D In the SQL model files

Sources are defined in sources.yml files to list raw tables and their metadata.

Why should you use source() instead of hardcoding table names?

A To improve data lineage and documentation

B To speed up query execution

C To automatically create tables

D To encrypt data

Using source() helps track where data comes from and documents your sources clearly.

Can source() reference tables outside your dbt project?

A No, only tables inside the project

B Only if you use a special plugin

C Yes, if defined in <code>sources.yml</code> and accessible

D Only for views, not tables

source() can reference any table accessible by your warehouse if defined properly.

What is the correct syntax to reference a source table named 'orders' in source 'raw_data'?

A <code>source('orders', 'raw_data')</code>

B <code>ref('orders', 'raw_data')</code>

C <code>ref('raw_data', 'orders')</code>

D <code>source('raw_data', 'orders')</code>

The syntax is source('source_name', 'table_name'), so source('raw_data', 'orders') is correct.

Explain how the source() function helps manage raw tables in dbt projects.

Think about how you keep track of where your data comes from.

Describe the steps to set up and use the source() function for a new raw table.

Start from configuration, then usage, then benefits.