Why Cannot the DROP operation Be Performed on a Backed-up Hive Table?

Question

Why cannot the DROP operation be performed for a backed up Hive table?

Answer

Snapshots have been created for an HDFS directory mapping to the backed up Hive table, so the HDFS directory cannot be deleted. As a result, the Hive table cannot be deleted.

When a Hive table is being backed up, snapshots are created for the HDFS directory mapping to the table. The snapshot mechanism of HDFS has the following limitation: If snapshots have been created for an HDFS directory, the directory cannot be deleted or renamed unless the snapshots are deleted. When the DROP operation is performed for a Hive table (except the EXTERNAL table), the system attempts to delete the HDFS directory mapping to the table. If the directory fails to be deleted, the system displays a message indicating that the table fails to be deleted.

If you need to delete this table, manually delete all backup tasks related to this table.