Default Managed Tables
In CDP, managed tables are transactional tables with the
property by default. You must be aware of the new default behavior of modifying file systems on
a managed table in CDP and the methods to switch to the old behavior.
New Default Behavior
- You can no longer perform file system modifications (add/remove files) on a managed table in CDP. The directory structure for transactional tables is different than non-transactional tables, and any out-of-band files which are added may or may not be picked up by Hive and Impala.
insert_onlytransactional tables cannot be currently altered in Impala. The
ALTER TABLEstatement on a transactional table currently displays an error.
- Impala does not currently support compaction on transaction tables. You should use Hive to compact the tables.
INSERT OVERWRITE, and
TRUNCATEstatements are supported on the insert-only transactional tables.
- If you do not want transactional tables, set the
DEFAULT_TRANSACTIONAL_TYPEquery option to
NONEso that any newly created managed tables are not transactional by default.
External tables do not drop the data files when the table is dropped. To purge the data along with the table when the table is dropped, add
external.table.purge = truein the table properties. When
external.table.purgeis set to
true, the data is removed when the
DROP TABLEstatement is executed.