Oracle: External Tables

Types of external tables

There are four types of external tables. Depending on the type, Oracle uses a different driver to access the data in the external table:

Driver
Oracle loader	The default driver. External data is read only and resides in a text file (for example a CSV file).
Oracle datapump	The external data is stored in binary dump files. Exporting data to the external location is possible, but the DML statements `update` and `delete` cannot be used to modify the external data.
Oracle HDFS	Data is stored in a Hadoop distributed file system (HDFS)
Oracle HIVE	Data is stored in Apache HIVE.