The behavior for dropping a namespace. - RESTRICT (default): the namespace should not contain any table or child namespace when drop is initiated. If tables are found, the server should return error and not drop the namespace. - CASCADE: all tables and child namespaces in the namespace are dropped before the namespace is dropped.
The mode for dropping a namespace, deciding the server behavior when the namespace to drop is not found. - FAIL (default): the server must return 400 indicating the namespace to drop does not exist. - SKIP: the server must return 204 indicating the drop operation has succeeded.