What does the command 'dbt run --models +model_name' accomplish?

The command 'dbt run --models +model_name' specifically instructs dbt to run the designated model along with all of its upstream dependencies. This is essential for several reasons.

First, in dbt, models are often interlinked through relationships such as references, where one model is dependent on another. If 'model_name' has dependencies—other models that must be executed first for 'model_name' to work correctly—this command ensures that all required prerequisites are run beforehand. It builds a clear pipeline where the output of these upstream models serves as the input for 'model_name'.

This functionality fosters a more efficient and streamlined data transformation process, ensuring that the entire hierarchy of dependent models is maintained, which is crucial for accurate data analysis. Running only the specified model would potentially lead to incomplete or incorrect data outputs if its dependencies haven't been updated or run.

In essence, choosing this command enables dbt users to efficiently manage their transformation workflows by streamlining the process of handling dependent data models.