What is... a Catalog?

In Databricks, a catalog is the primary unit of data organization within the Unity Catalog data governance model. It serves as the top-level container for organizing data and is part of a three-level namespace hierarchy: catalog, schema, and table. Each catalog can contain multiple schemas, which in turn can hold tables, views, volumes, models, and functions. Catalogs help in logically isolating and categorizing data, often reflecting organizational units or different environments like production and development. They also provide a structured way to manage data access and permissions efficiently.

Unity Catalog's Object Model

For instance, you might have separate catalogs for sensitive customer data and non-customer data to ensure proper data governance and security.