What is the default behavior for Custom Schema in dbt?

The default behavior for Custom Schema in dbt is to append the custom schema to the target.schema. This means that when you specify a custom schema in your dbt project, dbt takes the base schema defined in your target configuration and adds the specified custom schema to it, allowing for flexibility and organization in how tables and models are structured within the database.

This approach allows users to manage and categorize their models more efficiently while ensuring that they remain in the appropriate database context defined by the target settings. By appending to the target.schema, dbt helps maintain a structured environment, making it easier to manage multiple versions or variations of models without interfering with the existing schema structure.

In contrast, other options imply a more disruptive behavior, such as overwriting or creating entirely new schemas without linking them to the existing structure, which is not aligned with the intended use and flexibility offered by dbt. This design choice aims to facilitate a more organized and manageable data environment for analytics engineers.