Switch a hive table between managed table and external table - ayushmathur94/Spark GitHub Wiki
Make your table MANAGED first:
hive> ALTER TABLE abc SET TBLPROPERTIES('EXTERNAL'='FALSE'); Then truncate
hive> truncate table abc;
And finally you can make it external again:
hive> ALTER TABLE abc SET TBLPROPERTIES('EXTERNAL'='TRUE');
hive> Describe FORMATTED table_name;