Databricks previews table transfers between data catalogs

Databricks is offering REGISTER and UNREGISTER operations in a Unity Catalog private preview, allowing customers to transfer management of a data table between catalogs without copying its files. The company says it contributed UNREGISTER to the Apache Iceberg REST catalog specification. UNREGISTER removes the old catalog's table entry without deleting the underlying data and returns the latest metadata location. REGISTER uses that location to attach the table to its new catalog. The sequence prevents two catalogs from independently coordinating writes to the same table. Production migrations still require safely stopping writers and repointing jobs; customers must contact their account team to try the preview.