Why is Unity Catalog needed?

Unity Catalog is Databricks’ unified metadata layer that provides centralized governance across all data assets. It stores metadata for tables, views, files, and machine‑learning models, enabling consistent schema enforcement and lineage tracking. With Unity Catalog, you can apply fine‑grained access controls at the database, table, column, or even row level, which is essential for compliance with regulations like GDPR or HIPAA. It also integrates with external identity providers (Azure AD, AWS IAM) and secret stores, simplifying authentication. Additionally, Unity Catalog supports data masking, auditing, and automated catalog updates, reducing operational overhead. In short, Unity Catalog gives you a single source of truth for data, improves security, and simplifies governance across multiple workspaces and cloud environments.