An open-data team must delete raw 311 attachment files after a mandated municipal retention window. What should they apply in Unity Catalog governance?

A data retention policy that removes raw 311 attachments after the mandated municipal retention window is the correct Unity Catalog governance control for the open-data team. Data retention policies in Unity Catalog automate lifecycle enforcement on raw objects, ensuring compliance with municipal record laws without manual intervention or external oversight.

A row filter policy that restricts raw 311 attachment access during the mandated retention window only controls row visibility at query time; it does not delete the underlying files after the retention window, so it fails the removal mandate. A column mask policy that redacts raw 311 attachment metadata during the mandated retention window only redacts column values at query time, leaving the raw attachments untouched and failing to meet the statutory deletion mandate. An audit log policy that tracks raw 311 attachment access during the mandated retention window only records access history; it does not delete the files after the retention window, so it fails the removal mandate.

Exam caveat: Data retention policies differ from backups and snapshots—retention policies physically remove data after the window, while backups preserve historical copies for recovery. The retention policy cannot be overridden by user request; it is a durable governance control.

Operational check: Configure a retention policy on the 311 raw attachments folder that targets the mandated window (e.g., 7 years), verify policies are evaluated at schedule time (not request time), test a dry-run policy to forecast deletion, run a post-policy scan to confirm removed attachments are no longer queryable, and document the policy in compliance audit logs.