Hi @m208205, The Unity Catalog and Hive handle partitions differently, and this distinction is important when migrating existing partitioned Delta tables from Hive to Unity Catalog.
Here are the key differences:
-
Partition Management:
- Unity Catalog: When using Unity Catalog, you wonโt be able to directly manipulate partitions using Hive commands. Unity Catalog manages partitions in its own way.
- Hive: In Hive, you can use commands like
ALTER TABLE ... ADD PARTITION
or ALTER TABLE ... DROP PARTITION
to modify partitions directly.
-
Table History Migration:
- When you run
CREATE TABLE CLONE
to migrate tables from Hive to Unity Catalog, the table history is not migrated. Any tables cloned to Unity Catalog are treated as new tables.
-
Managed Tables in Unity Catalog:
- Itโs recommended to create managed tables in Unity Catalog. Managed tables are the preferred way to create tables because they provide better control over metadata and lifecycle management.
For more detailed information, you can refer to the official documentation on upgrading Hive tables and views to Unity Catalog. This guide will help you navigate the migration process effectively. If you have any further questions, feel free to ask! ๐