What is the purpose of the `ref()` function in dbt?

The ref() function in dbt is primarily used to reference another model within the dbt project. This function plays a crucial role in dependency management, as it allows dbt to understand the relationships between different models and ensures that they are built in the correct order.

When you use ref(), you're not just providing a way to call another model; you're also enabling dbt to track dependencies automatically. This means that if a model changes, dbt can figure out which downstream models need to be refreshed based on that change. This built-in dependency resolution helps maintain data integrity and simplifies the workflow when managing complex data transformations.

In contrast to other options, such as running a model in isolation or documenting models in a YAML file, the ref() function is specifically designed to handle dependencies between models. Generating reports on model execution history does not relate to the primary function of ref(), which is focused on establishing connections between models for proper execution order and ensuring that data transformations flow correctly through the pipeline.